Yet the "Change Begins with Us" placards held aloft at recent Romney campaign rallies bear a striking graphic resemblance to those "Change We Can Believe In" posters that appear at Barack Obama's rallies.
And Mike Huckabee has emerged as a major Republican contender by being as different as possible from Bush. Huckabee has even attacked the "arrogant bunker mentality" of the administration's foreign policy. He occasionally minimizes the import of those words but does not repudiate them.
That McCain's re-emergence arose more from opposition to Bush than from the Arizona senator's embrace of the surge in Iraq was made clear by the New Hampshire primary exit polls.
Among McCain's voters, 54 percent had a negative view of the Bush administration (compared with 41 percent of Romney's voters), and an astonishing 42 percent of McCain's voters disapproved of the Iraq War, compared with just 22 percent of Romney's supporters.
These figures may seem surprising. McCain has been a consistent supporter of the Iraq War and said recently that he could imagine keeping American troops in Iraq for 100 years.
When asked about this during an ABC News interview the day after his New Hampshire victory, McCain added with a flourish: "Could be 1,000 years or a million years."
Yet McCain's maverick image and the fact that he regularly emphasizes the aspects of Bush's Iraq policy that he opposed seem to have established him as his party's closest thing to an anti-Bush candidate.
This helps explain why McCain did far better among self-described moderates and liberals in New Hampshire than among conservatives. A new Washington Post/ABC News poll showed him stronger in the center than on the right.
Before the turn of the year, the Republican contest did not have an ideological character, and the party's presidential candidates were reluctant to distance themselves from Bush on the theory that many in the party remained loyal to the president.
For now, former New York City Mayor Rudy Giuliani and former Sen. Fred Thompson seem the least inclined to back away from the Bush record. Both have been losing ground nationally, though Thompson still hopes to do well on Jan. 19 in South Carolina, a state that saved Bush's presidential candidacy eight years ago.
But with the president's standing in the polls remaining low and the public's intense desire for change spilling across party lines, Bush may find himself on the sidelines, watching a campaign built around a bipartisan repudiation of his legacy.
The newly revived McCain will have to tread carefully, maintaining his image of independence to hold his moderate base while reaching out to conservatives in states where middle-of-the-road voters play a modest role in Republican primaries.
Romney, needing a victory Tuesday in Michigan to remain competitive, abruptly shifted from an image of himself as the new embodiment of Ronald Reagan to a nostalgic appeal to the memory of his late father, George Romney, a liberal who would be out of step with today's GOP.
Huckabee hopes he will draw enough support from evangelical Christians to win in South Carolina, while Giuliani is betting everything on a strong showing at the end of the month in Florida.
In a Republican Party more unsettled and disheartened than at any point in the modern era, it is almost certain that the contest will take another unexpected turn.
Tony Fabrizio, an experienced Republican pollster, suggested in an interview just how peculiar the year could get.
Should the ultra-maverick Huckabee - rather than Romney, Thompson or Giuliani - emerge as the main alternative to McCain, it is likely that Republican leaders would reluctantly rally to a man so many of them had resisted. "Only Mike Huckabee could turn John McCain into the establishment candidate," Fabrizio said.
This is the politics the Bush presidency has wrought.
E.J. Dionne's e-mail address is firstname.lastname@example.org.
2008, Washington Post Writers Group