IMPEACH BUSH

For Americans, the 4th of July is a time for celebration. For George Bush however, today's Independence Day holiday is another date in the calendar of an imploding presidency without parallel in recent history.

The latest, albeit probably relatively minor, blow to Mr Bush's standing was his move on Monday to commute the 30-month jail sentence imposed on Lewis "Scooter" Libby, Vice-President Dick Cheney's former chief of staff, for perjury in the CIA leak case.

The decision has been greeted with predictable outrage by Democrats, who accuse Mr Bush of cronyism and contempt for the law. But although polls have shown that some 70 per cent of Americans opposed any idea of a pardon for Libby, so weak has Mr Bush become that the decision could actually strengthen him - by shoring up support among the conservative faithful, Mr Bush's core constituency, who believe the real outrage was Libby's conviction in the first place.

"I am very happy for Scooter Libby. This will allow a good American, who has done a lot for his country, to resume his life," said Fred Thompson, unabashed conservative and soon-to-be-declared Republican presidential candidate, who helped organise a Libby defence fund.

At his daily briefing yesterday, the White House spokesman Tony Snow not only defended the decision to commute the prison term, but even held the door open to a full pardon.

Although Libby has been spared jail, he still faces a $250,000 (£124,000) fine, two years' probation, and the lasting blot on his reputation of a felony conviction's - not to mention an estimated $5m in legal costs that friends are scrambling to cover. "This is hardly a slap on the wrist, it's a very severe penalty," said Mr Snow, denying that the commutation was to prevent Libby from revealing embarrassing secrets as he continued his appeal efforts from behind bars.

But the Libby affair may be quickly supplanted by new pressures on Mr Bush. The Democrat-controlled Congress is raining subpoenas on White House and Justice Department officials over scandals involving warrantless domestic wiretapping and the dismissal of eight federal attorneys last year.

As a court clash with the legislature looms, the President is under continuous pressure to sack the Attorney General, Alberto Gonzales, an old Texas friend, and much of that pressure is coming from Mr Bush's Republicans on Capitol Hill, a sign of how he is losing control of his own party.

Thus far, the most vivid evidence of his crumbling authority was the Republican rebellion that led to defeat of immigration reform, a measure vigorously championed by the President. Its demise ended Mr Bush's last hope of a significant second term legisative achievement, and sealed his status as the lamest of lame ducks.

But a more ominous challenge looms in September when - barring clear evidence that his troop surge is working - Republicans could join with Democrats to force a change in strategy on Iraq, the issue that above all is destroying his presidency. Thus far, his own party has kept ranks behind him. But with the 2008 elections less than 18 months away, the cracks are growing, and last week saw the most important defection yet, of Richard Lugar, the senior Republican on the Senate Foreign Relations Committee.

Mr Bush's unpopularity is now challenging long established records. Some presidents briefly have been more disliked: Jimmy Carter slipped to a 21 per cent approval rating in July 1980, four months before he was trounced by Ronald Reagan in that year's election. But even at the height of opposition to the Vietnam War, Lyndon Johnson's approval ratings averaged above 40 per cent in 1967-68.

Not since Harry Truman in the early 1950s has a president been as unloved for as long as Mr Bush. He slipped below the 50 per cent mark in spring 2005, and for the past year and a half, he has been stuck in the mid-30s. In one poll he fell to 28 per cent, worse even than his father at his lowest before he lost to Bill Clinton in November 1992.

With public dissatisfaction over Iraq continuing to grow, and the "right track, wrong track" barometer showing an unprecedented 74 per cent of Americans convinced the country is heading in the wrong direction, Mr Bush will probably remain deeply unpopular for the 18 months remaining until he leaves office in January 2009.