Three front-page stories on a single day last week testified to the unraveling of the Bush presidency.

The lead story in The Post on Thursday reported that "the Senate defied the White House yesterday and voted to set new limits on interrogating detainees in Iraq and elsewhere," with 46 Republicans joining the Democrats to pass restrictions on prisoner abuse so unacceptable to President Bush that he has threatened his first veto.

A second story on the same page recounted that "the conservative uprising against President Bush escalated yesterday as Republican activists angry over his nomination of White House counsel Harriet Miers to the Supreme Court confronted the president's envoys during a pair of tense closed-door meetings."

Participants described it as the biggest split with the GOP base in his five years in office.

And elsewhere on the page was the news that the Central Intelligence Agency's director had rejected a recommendation from its inspector general that he convene a formal "accountability board" to judge the possible culpability of senior officials in the failures that preceded the Sept. 11, 2001, terrorist attacks. The action triggered a statement of concern from the Republican chairman of the Senate intelligence committee and criticism from families of Sept. 11 victims.

These developments came against a background of rising conservative criticism in Congress of runaway spending, of continuing investigations of the administration's faltering response to Hurricane Katrina and of criminal indictments and grand jury probes that have forced out the chief White House procurement officer and the House Republican majority leader and that may implicate other top officials of both branches.

Coming when Bush is recording his lowest-ever job-approval scores, this has led as sober an analyst as John Kenneth White of Catholic University to describe this as "a presidency on life support." Noting the precipitous decline in Bush's ratings from moderates and independents, White argues that continuing problems -- notably the war in Iraq, the high cost of gasoline and home heating fuels, and an unending stream of deficits -- are likely to plague Bush indefinitely

A valuable historical perspective on all this came from Stephen Skowronek of Yale University in a talk to the American Political Science Association just before Labor Day. At the time, it seemed a bold -- even questionable -- thesis. Now it looks prescient.

Skowronek, a presidential scholar, defined Bush as "an orthodox innovator," meaning someone who inherits a governing doctrine from others -- in his case, Ronald Reagan -- but applies it in different circumstances and with different techniques.

Other presidents of the same ilk, he said, include James Polk, Theodore Roosevelt and Lyndon Johnson. Johnson, for example, took a number of ideas that had been on the shelf since New Deal days and tried to apply them to a hugely different time, succeeding spectacularly with a Medicare plan rooted in Social Security but failing disastrously when he applied the analogy of Hitler to Ho Chi Minh.

Skowronek said that historically what leads to ultimate failure for orthodox innovator presidents is "sectarian infighting." They fail, he said, not because the political opposition becomes so strong but because their own supporters fall out among themselves -- some insisting on the original orthodoxy of the inherited philosophy, others demanding more change to adapt to the new conditions.

When Skowronek spoke, barely a month ago, I was skeptical. But now such strains are plainly visible inside Bush's coalition. Some fiscal conservatives are demanding a return to smaller government and balanced budgets while others in the coalition -- neoconservative hawks and worried Southern elected officials -- back Bush in pledging "whatever it takes" to win in Iraq and repair the Gulf Coast.

Similarly, among social conservatives, some are no longer satisfied with Bush's personal assurances that his tight-lipped Supreme Court choices will actually roll back the school prayer, affirmative action and abortion rulings now in effect, while others applaud Bush for taking what they regard as the course of prudent ambivalence.

Skowronek said the long rivalry between Bush and Sen. John McCain -- something that flared again in last week's fight over the treatment of detainees -- was reminiscent of the battles between Polk and Martin Van Buren, and between LBJ and Robert Kennedy -- fights that split their parties wide open.

But he also noted that the unprecedented organizational strength and top-down control of the Republican Party forged in the Bush years served for a long time to keep these internal pressures from erupting.

Whether that discipline will continue to hold through Bush's lame-duck years is another -- and very different -- question. It must be keeping Karl Rove awake at night.

davidbroder@washpost.com

Commentary: