IMPEACH BUSH

1. KARL ROVE

Dubbed the "architect" and "Bush's brain", Rove plotted to rise of George W Bush and departed the White House after the disastrous 2006 mid-term elections. Successful punditry is a combination of real political experience, intellectual nimbleness, a provocative turn of phrase and a coherent point of view. Rove, a Fox News commentator and contributor to Newsweek and the Wall Street Journal, has all these qualities.

Democrats may protest that they would rather see him in jail than on their television screens but they can't help noting what he says. Whether outlining what the Democrats should do or outlining John McCain's rocky path to victory (and McCain has followed his advice almost to the letter), Rove's take is important and often surprising. Expect the name Rove to come up frequently on the campaign trail – and in coverage of it.

2. CHRIS MATTHEWS

Motor-mouth MSNBC presenter of "Hardball" show, Matthews is a former Jimmy Carter speechwriter and aide to Tip O'Neill when he was Speaker of the House. He is believed to be contemplating running as a Democrat for the Senate in his native Pennsylvania. His ratings are not the highest but Matthews punches above his weight – and shouts above the hubbub.

With his infectious enthusiasm for politics, Matthews has pushed back hard against what he sees as the cynicism of Hillary Clinton's campaign. Mocked for saying that Barack Obama sent a "thrill up my leg" and accused by Clinton aides of being a misogynist, Matthews has bounced back. Always part of the conversation, his return to full-time politics would be journalism's loss.

3. SEAN HANNITY

Fast-talking, opinionated and unrelenting in his pursuit of targets, Hannity's performances on Fox News Channel's Hannity & Colmes, as well as his radio show, the second highest rated in the country, have made him one of the most significant voices in America today. Not forgetting the Sunday night show Hannity's America, he is probably on air more than any other of his ilk.

Fortune magazine said in 2005, "If you agree with his conservative worldview, you're deemed a ‘great American' If you don't, you're a pusillanimous blame-America-firster, who might as well pledge allegiance to France." Single-handedly brought the issue of Barack Obama's association with unrepentant former domestic terrorist Bill Ayers to national attention, if the Illinois senator fails to win the White House, Hannity could well be one of the principal reasons.

4. RUSH LIMBAUGH

The undisputed king of talk radio, Limbaugh invigorates and enrages in equal measure. A standard bearer of the conservative movement, he was bitterly disappointed with the choice of John McCain as Republican nominee, and declared he might withdraw support from his party, saying "I would just as soon the Democrats take the hit".

Since then, he has concentrated on his "Operation Chaos" – urging Republicans voters to support Hillary Clinton so the Democratic nomination race will be prolonged and Barack Obama discredited. John McCain has declared: "I don't listen to him." But thousands of the voters he needs in November do.

5. JOHN HARRIS AND JIM VANDEHEI

Founders of Politico.com, the website that has revolutionised US election coverage. Formerly political editor and political correspondent of the Washington Post, the pair have overseen a stunningly successful and ground-breaking multi-media venture, nurturing established talents such as columnist Roger Simon and correspondents Mike Allen and Jeanne Cummings as well as new ones like bloggers Ben Smith and Jonathan Martin and video prodigy James Kotecki.

Both assured television performers, Harris and VandeHei's joint pieces helping establish major changes in the campaign narrative have earned them the soubriquet VandeHarris. Harris co-authored the highly influential "The Way to Win: Taking the White House in 2008". Post-election, look for Politico to do with reporting the White House what they have with campaign coverage.

6. MATT DRUDGE

To place one of the most reclusive figures in modern journalism in the top tier of 50 egotistical and omnipresent pundits might seem perverse. But Drudge's influence is so pervasive that his www.drudgereport.com website is more capable than any other media outlet of changing the course of the 2008 election.

His detractors claim that all he does is link to other people's stories. But that selection shapes the election narrative and his periodic exclusives – dramatically signalled by a siren and underlined red lettering – can be explosive. Hillary Clinton has tried to woo him. If John McCain or Barack Obama can win him over between now and November it could be worth several percentage points in the polls.

7. TIM RUSSERT

Mario Cuomo, writing in Time when it placed Russert 72nd among the 100 most influential people in the world, called him "among the most astute, discerning and relentless pursuers of truth in the nation". His probing questions have the ability to alter the course of a campaign.

This was best demonstrated when he picked up Hillary Clinton's hesitation over driving licences for illegal immigrants at a debate in October 2007 and didn't relent until she was thoroughly embarrassed. It was the first chink in her armour of "inevitability". With four million viewers every Sunday morning, Meet the Press is required viewing and a must-do appearance for aspiring presidents. Russert took Al Gore apart in 2000. On Sunday, Barack Obama goes into the lion's den with Russert – potentially a make or break hour for the candidate.

8. JON STEWART

The liberal host of the Daily Show on Comedy Central mixes comedy and political satire, but it is his serious moments that have carried him into the realm of punditry. A frequent of critic of George W Bush, he also embarrassed his friend John McCain for speaking at Jerry Falwell's Liberty University, having previously denounced the preacher and his ilk as "agents of intolerance". McCain was forced to concede that he was descending into the "crazy base world" of politics.

His show gets more serious as it endures, with guests such as Howard Dean and Harry Reid in the space of a week. A relentless critic of combative pundits, he is widely judged to have humiliated Tucker Carlson, formerly of CNN and MSNBC, and Chris Matthews during on-air jousts.

9. DAVID BROOKS

The moderate conservative New York Times columnist's changing reactions to Barack Obama have been one step ahead of the pack during the extended primary season. A regular on the highbrow The NewsHour with Jim Lehrer on PBS. He initially overcame doubts to swoon over the Illinois senator, in part because of a shared admiration for the philosopher Reinhold Niebuhr.

By 2008, he was the first commentator to declare his discomfort with at the cult-like atmosphere at Obama rallies, a view that then became an everyday part of the media discussion. A long-time admirer of John McCain who still holds affection for Obama, he could be a political weathervane in the general election.

10. MARK HALPERIN

Everything in Halperin's career has been a success, from founding ABC's Note – the must read of the 2004 campaign - to his current "the Page" on Time.com, via the widely read The Way to Win: Taking the White House in 2008 with John Harris.

What distinguishes his reported blog and his commentary is the access to highly placed sources and the leaks they provide him. As a ubiquitous TV analyst his views will be carefully listened to during the rest of the campaign. His on-line network news summaries, campaign events lists and his pithy, sometimes unvarnished (he apologised this year for revealing that John Edwards thought that Barack Obama was "kind of a pussy") analysis make him a first stop for political reporters and campaign junkies.

11. STEPHEN COLBERT

It is often said that Fox's Bill O'Reilly is the model for Stephen T Colbert, the self-indulgent, bombastic and inaccurate character who chairs the Colbert Report on Comedy Central.

Colbert's id has been described as a "well-intentioned, poorly informed high-status idiot". Through show's the phony news and election coverage, his mainly young audience nonetheless feels it is getting the spiritual truth about the campaign.

12. BILL O'REILLY

Fox News Channel's top-rated presenter with 2.3 million viewers offers a nightly tour de force, cajoling, confronting and sometimes outraging his guests.

The O'Reilly Factor pulled off a coup, finally persuading Hillary Clinton to be interviewed by the network for the first time, and may have done her chances against Barack Obama no harm at all. The show is credited with pioneering the opinionated, presenter-led format that has now become the norm.

13. KEITH OLBERMANN

Host of MSNBC's Countdown, Olbermann,a former sports commentator, is one of the rising stars of politics on television and is at the centre of his cable channel's attempt to become the edgy, liberal choice for those in their 20s and 30s.

Supportive of Barack Obama, Olbermann's on-air eviscerations of Hillary Clinton's campaign have been only slightly milder than his contemptuous monologues about President George W. Bush. Seen as a successor to his MSNBC rival Chris Matthews, he has conducted a vocal feud with the conservative Bill O'Reilly of Fox News. A disciplined and smooth performer.

14. CHUCK TODD

Political director of NBC News, Todd is a frequent on-air presence and talking encyclopedia on modern election campaigns. Previously the editor of National Journal's daily Hotline briefing, which became the definitive guide to what was happening in American politics.

Now oversees MSNBC's "First Read" online election guide. Sober, measured, without a discernible party leaning and extremely well connected to the different campaigns, Todd's voice is one of the most listened to in Washington.

15. BILL MAHER

Comedian, actor, writer and producer, Maher has found the perfect niche with his weekly HBO show, where his astute wit works to the full. An A-List guest line up, and discussion of a range of topics mean there is rarely a dull moment.

His opening monologue and the New Rules segment wrapping up the week's (mainly) political news have offered some of the sharp-eyed and funny observations on the campaign.

16. GLENN BECK

A CNN Headline News presenter, host of America's fourth most popular talk radio show, Beck's recent "An Inconvenient Book" took on not only Gore's "An Inconvenient Truth" film about global warming but also the United Nations, radical Islam, political correctness and media bias – amongst many other targets.

One of the conservatives jockeying to be anointed as the eventual successor to talk radio giant Rush Limbaugh, Beck – far from a toer of the Republican party line – will be one of the key figures John McCain will need to get on board.

17. ANDREW SULLIVAN

British-born writer who embraced blogging early and whose Daily Dish blog, now parented by Atlantic Monthly, drives much of the American political conversation. A self-described conservative who supported the Iraq invasion, he has become an unstinting critic of President Geroge W. Bush, the Iraq war and US interrogation practices.

Sullivan's influential article "Why Obama Matters" last December encapsulated why he and many other former Republican voters were entranced by the Illinois senator's candidacy. But Sullivan has respect for many of John McCain's positions. Also appears regularly on television and writes a weekly newspaper column.

18. FRANK LUNTZ

Luntz's televised focus groups, shown on Fox News, immediately help define which candidate has won or lost a debate. A crafter and analyst of political language and campaign messages, he is adept at telling you what politicans mean by what they are saying as well as how they should be saying what they mean.

Although a Republican, Luntz is not afraid of telling his own party how it is. He has consistently refused to write Hillary Clinton off and has warned that Barack Obama would be a tough candidate for John McCain to beat. Has advised Tony Blair and David Cameron.

19. DONNA BRAZILE

The first African American to run a presidential campaign, she ended up a loser with Al Gore in 2000, but has become a regular contributor to CNN's political coverage. Her punditry offers direct, plain-spoken advice to candidates of both parties.

A super-delegate thanks to her chairmanship of the Democratic National Committee's Voting Rights Institute, she has not said she agrees with House Speaker Nancy Pelosi that super-delegates should not overturn the will of Democratic voters in the primaries, but neither has she said she disagrees.

20. JOE KLEIN

One of the most readable columnists today, Democrats take notice if he spots a shift in the electoral zeitgeist.

His column in Time has been questioned for its accuracy on occasion, but remains required reading. The author of the best-selling Primary Colours on Bill Clinton's 1992 primary campaign, he is an admirer of George W Bush the man, if not his policies. Caused a stir earlier this year by suggesting that Bill Clinton was unwittingly sabotaging his wife's campaign.

21. DAVID GERGEN

The pundits most in demand are those who have served in the White House in a role close to a president. Gergen scores a double in this respect because he was Ronald Reagan's director of communications and then a counselor to Bill Clinton. Although a Republican (he also played roles in Richard Nixon's and Gerald Ford's administrations), his credentials span both parties.

A Harvard professor at the John F. Kennedy School of Government, CNN analyst and US News and World Report contributor, Gergen's stance often helps define the received wisdom on a given issue.

22. DICK MORRIS

Another Republican brought in as an adviser to Bill Clinton, the pollster, author, consultant, columnist and commentator has dogged the Clintons ever since. Armed with inside knowledge of the Clinton White House, he used his columns in "The Hill" newspaper to deliver a devastating critique of Hillary Clinton's motives and relationship to the truth.

A frequent face on Fox News, Morris has often been wide of the mark in his predictions. He once declared Mrs Clinton to be the inevitable Democratic nominee and now argues that she cannot defeat Barack Obama. Shrewd analysis and inside knowledge, however, mean his is a voice that cannot be ignored.

23. MIKE ALLEN

One of the hardest-working and best-connected news journalists in the business, Allen does not fit the typical profile of a pundit because he shies away from airing political opinions. But his morning "Playbook" email has become a must-read in Washington, framing the news agenda for the day.

With his wide array of sources, impeccable judgement and seeming capacity to operate without sleep, Allen, formerly of The Washington Post Time magazine, is one of the major reasons behind the huge success of the website and newspaper "Politico".

24. LAURA INGRAHAM

Since launching in 2001, her eponymous radio show has grown rapidly in popularity, and is now broadcast on 306 stations nationwide.

The author of three popular books on society and culture, Ingraham is one of the most voluble detractors of liberals in the media, academia and the entertainment industry, and reserves some of her sharpest scorn for Hillary Clinton.

25. MICHAEL SAVAGE

With ten million listeners, he is the third most listened-to Right-wing talk show host, but directs most of his brash, passionate ire at cultural rather than political targets.

A liberal in the 1960s, by the mid 2000s a brief stint on MSNBC ended when he wished the curse of Aids upon a listener who turned out to be a prankster. As Michael Weiner, his proper name, he is a widely-published homeopathy expert.

26. ARIANNA HUFFINGTON

With a talking head career that goes back to Radio 4's Any Questions in the 1970s Huffington (neé Stassinopoulos) is now one of the most recognisable figures in the American commentariat, for her TV appearances alone.

Her blog the Huffington Post completed her journey from Right-wing to Left-wing and saw her become a major media supporter of Barack Obama, though the Post did break the damaging "bitter" story.

27. PAT BUCHANAN

With his service to presidents Nixon, Ford and Reagan, and three tilts at the presidency, Buchanan brings a rare experience and perspective to the clamour around the current campaign.

Manages to keep his Right-wing urges in check to provide some of the sharpest analysis on MSNBC, the most liberal network.

28. JAMES CARVILLE

Fully deserves the title of media personality, for his theatrical demeanour, ready laugh and sharp wit. Still admired for running Bill Clinton's successful 1992 campaign, he remains loyal to his old boss, going as far as to call fellow Clinton traveller Bill Richardson "Judas" for endorsing Barack Obama.

Will be interesting to see how supportive he is of Obama against McCain.

29. RON FOURNIER

A traditional Associated Press reporter who made his name covering the Clintons in Arkansas, Fournier's new role is to produce game-changing big-picture pieces about the 2008 election. His "Hillary's flight of fantasy" and "Obama walks the arrogance line" have helped shape television and newspaper coverage across the country.

Although he rarely appears on television and his influence is primarily behind the scenes, Fournier's newly-opinionated pieces are "game changers" that place him firmly in the higher ranks of the Washington pundit class.

30. PEGGY NOONAN

A former Ronald Reagan speechwriter turned author, "Wall Street Journal" columnist and frequent talking head, Noonan is viewed by many as a keeper of the Republican flame. She has not hesitated to be critical of President George W. Bush.

Noonan has an ability to surprise that means she is listened to by liberals as well as conservatives. She took the side of Senator Jim Webb, a Democrat, who had a terse exchange with Mr Bush over the Iraq war and has praised Barack Obama.

31. JUAN WILLIAMS

Continues to be a contributing political analyst for the Fox News Channel, and a coherent critic of Obama and Rev Jeremiah Wright.

A vocal opponent of the ‘victim culture' within the black community, he accused the pastor of ‘wacky and bitterly divisive racial rhetoric' and said Obama's decision to still sit in his pews indicated a crisis in black leadership.

32. WILLIAM KRISTOL

The former chief of staff to Vice President Dan Quayle is a ubiquitous media presence. Editor of the conservative "Weekly Standard" magazine, he is a Fox News contributor and newly-minted "New York Times" columnist – the Right-wing fox in the liberal hen coop.

A staunch defender of Israel and committed neo-conservative, he is a strong advocate of John McCain's muscular foreign policy and the Iraq war.

33. ROLAND MARTIN

A regular face on CNN and a radio host, Martin has repeatedly called for the media to show more balance and understanding on the Rev Jeremiah Wright issue, but hasn't been afraid to criticise the pastor or Barack Obama when he sees fit.

Like Wright, he is a black pastor from Chicago, and has a strong perspective on an issue that will run until November, if Obama seals the nomination.

34. HOWARD KURTZ

Long-time media correspondent for the "Washington Post", author, blogger and presenter of CNN's "Reliable Sources", Kurtz is the media's internal watchdog, helping shape coverage by critiquing political journalists – identifying and monitoring trends such the media's infatuation with Barack Obama and fondness for John McCain.

Still an old-fashioned shoe-leather reporter, he also holds candidate's to account by detailing their openness or otherwise and the way politicians manipulate the press.

35. JOE TRIPPI

One of the most respected Democratic strategists around, the quick-thinking Trippi has now brought his recent experience with the John Edwards campaign to bear on CBS, offering a competitor's view of the successes and failures of the Clinton and Obama campaigns.

A pioneer of Internet electioneering with Howard Dean in 2003-04, he however remains a loyal party man and keeps his harshest views to himself.

36. NEWT GINGRICH

The author of the Contract with America and leader of the Republican Revolution in 1990s has lost some of his lustre after the loss of Congress in 2006, but remains one of the most persuasive critics of the Democrats.

Will be a key man in Fox's assault on Obama or Clinton in the presidential election.

37. EUGENE ROBINSON

A regular on MSNBC, Robinson stars in his bi-weekly Washington Post column that not only pulls apart the Bush administration but on more than one occasion, Hillary Clinton.

Obama is held to account for lapses in consistency, but Robinson has been one of the senator's most elegant cheerleaders, a role that will be useful as the campaign endures.

38. MICHAEL BARONE

Fox News pundit, US News and World Report columnist and American Enterprise Institute scholar, Barone also co-authors the definitive "Almanac of American Politics".

Although on the Right, his political analyses usually set aside ideology and are based on rigorous number-crunching and an unparalleled knowledge of the electoral map right down to precinct level. Has recently argued that Hillary Clinton is ahead in the popular vote and could yet defeat Barack Obama.

39. DEE DEE MYERS

Became the first female and the second youngest White House press secretary under President Bill Clinton. An MSNBC commentator, she was a consultant to "The West Wing" series and was widely believed to the model for the character C.J. Cregg.

Married to Vanity Fair political writer Todd Purdum, in her recent book "Why Women Should Rule the World" she argues that women are "better communicators, better listeners, better at forming consensus". Well placed to chip away at the traditional male domination of political punditry.

40. TONY SNOW

Former Fox news host and most recently press secretary to President George W Bush, the affable Snow has just signed on as a CNN commentator. Would probably have placed higher were it not for his long and debilitating battle with cancer, which he appears to have won.

A committed conservative, his fair-minded approach and unfailingly reasonable demeanour means he is listened to right across the political spectrum.

41. MARK SHIELDS

A former Senate aide and Democratic operative, Shields, 70, has a career that spans eight presidents.

With his syndicated columns and regular slot as the liberal pundit on the PBS show "The NewsHour with Jim Lehrer", Shields is one of the ultimate Washington opinion formers. Attributes include a shrewd historical perspective and sharp wit.

42. BILL BENNETT

Former Education Secretary under Ronald Reagan and National Drug Czar under George Bush Snr, Bennett is an author, speaker, radio host and CNN commentator.

A committed conservative and strong moralist – subtitles of his books include the terms "Moral Clarity", "Moral Collapse" and "Moral Poverty" – he also has a keen understanding of political strategy and does not hesitate to criticise Republicans..

43. PAUL BEGALA

A dedicated Democratic partisan and former aide to President Bill Clinton, Begala has one of the most acerbic tongues on television. Currently committed to Hillary Clinton's campaign, he is so contemptuous of Republicans that he will throw his weight behind Barack Obama with equal enthusiasm if the Illinois senator becomes his party's nominee.

Made waves recently when he said he had "nothing but contempt" for ousted Clinton chief strategist Mark Penn.

44. JEFFREY TOOBIN

CNN legal analyst and "New Yorker" with an easy, conversational manner and Rolls Royce brain. No one knows more about the inner workings of the US Supreme Court – an institution that is arguably more important to American life than the presidency.

A normally dispassionate commentator, he does not hesitate on occasion to accuse candidates of being dishonest or plain wrong. If Toobin turns against a politician, it can be a sign they're in trouble.

45. FRED BARNES

Writer with the conservative "Weekly Standard" and regular presence on Fox News. Proponent of the Iraq war and global warming sceptic, he has been one of the most loyal supporters of President George W. Bush.

A figure that conservative Republicans look to, how enthusiastically he backs John McCain could be a factor in whether party stalwarts turn out in November or stay at home.

46. MARK LEVIN

As a supporter of Mitt Romney, Levin failed in his bid to stop John McCain winning the Republican nomination. He now calls on his large radio audience to keep watch on the Arizona senator's claims to be a bona fide conservative.

When the Democrats finally have a nominee he will have to weigh up his disdain for McCain and his dread at the prospect of a Democrat administration.

47. JC WATTS

A regular contributor across various networks, Watts is the last African American to serve as a Republican in Congress.

Having criticised his party's candidates during primaries for failing to "show up" for black voters, the former American footballer is the sort of voice John McCain appears to be listening to as he attempts to reach out to African Americans.

48. PAUL KRUGMAN

The Princeton University economics and international affairs professor has been a strident critic of Barack Obama in his twice-weekly opinion piece for the New York Times, to the fury of many fellow Democrats.

One of the first to question the media's infatuation with Obama, his antipathy raised suspicions that he was being lined up for an advisory role in a Hillary Clinton administration, which he denied.

49. MARY MATALIN

An assistant to George W Bush and Dick Cheney until she resigned shortly before the Iraq invasion, Matalin remains an authoritative and sharp-witted Republican voice on the airwaves.

But she backed the wrong horse in Fred Thompson, and since moving into publishing is not the force she was when hosting her own radio show in the 1990s.

50. RACHEL MADDOW

One of the most acute minds among the analysts on Democrats' favourite cable network MSNBC, Maddow seems destined for greater things, having already debuted for Republican-baiter in-chief Keith Olbermann.

With an evening radio show on Air America, the former Rhodes Scholar has a sound platform from which to promote her unashamedly Left-wing, activist agenda.