MANCHESTER, N.H. – President Bush won't be on the ballot in November 2008, but the Republicans who want to be clearly believe their best chance comes by distancing themselves from their party leader.
The 10 candidates yielded Bush no quarter during a spirited two-hour debate Tuesday night, as they contrasted their positions on a host of issues with those of the unpopular president.
"It's a typical Washington mess," former New York Mayor Rudy Giuliani said of the immigration bill Bush wants Congress to approve.
• Follow the horserace for the presidency in FOXNews.com's You Decide 2008 Center.
"The president ran as a conservative and governed as a liberal," said Rep. Tom Tancredo of Colorado. "That is what has really been the basis, I think, of the distrust that has developed among the Republican base. It's well founded."
The criticism was all the more pronounced because it was leveled as Bush traveled overseas for an economic summit in Germany, where he already has encountered protesters equally critical of his governance.
"I never heard such a piling on of a sitting president who's of the same party," said Linda Fowler, a government professor at Dartmouth College. "They were as tough on him as the Democrats were."
Fowler attributed the criticism not just to polls, which show the president's popularity mired at 35 percent, but a recognition within the GOP that it must redefine itself if it is to avoid a clean sweep from power in 18 months.
"When parties are struggling with their identity, there is an attempt to go back to first principles, so in many ways, the most striking criticism was not just that the war had been handled incompetently, but that the party principles had been abandoned. That's the first step in positioning one's self to be the `true Republican,"' Fowler said.
One sketchpad for that definition was immigration, as Giuliani, Romney and Tancredo led the charge against Sen. John McCain of Arizona for co-authoring the Bush-backed legislation with Sen. Edward M. Kennedy of Massachusetts, a liberal Democratic icon.
"If they get across my fence, we sign them up for the Olympics immediately," said Rep. Duncan Hunter of California, a vocal opponent of the bill and a proponent of building more fencing along the U.S border with Mexico.
"For us to do nothing is silent and de facto amnesty," said McCain, using a word popular among critics of the legislation.
But a broader canvas was a question asking the candidates what had been Bush's biggest mistake in office.
"Spending," came the simple answer from Sen. Sam Brownback of Kansas.
Rep. Ron Paul of Texas said: "The president ran on a program of a humble foreign policy, no nation-building and no policing of the world, and he changed his tune."
Former Virginia Gov. Jim Gilmore said the party had abandoned its conservative principles, while former Arkansas Gov. Mike Huckabee said Bush had failed to clearly communicate his positions.
"We went to Washington to change Washington, and Washington changed us," said former Wisconsin Gov. Tommy Thompson, once a member of Bush's Cabinet. "If we're going to spend money like as foolishly and as stupidly as the Democrats, the voters are going to vote for the professional spender — the Democrat — not the amateur spender — the Republican."
In so doing, the GOP candidates clearly contrasted themselves with the man they hope to replace, even if it meant violating the cardinal rule of a Republican icon they routinely embrace.
"Thou shalt not speak ill of any fellow Republican," former President Reagan used to say.
Visit FOXNews.com's You Decide 2008 Center for complete coverage.