After voting in Crawford, Tex., President Bush returns to the White House. The GOP tried to avoid making the midterm elections a referendum on national leadership. (By Chip Somodevilla -- Getty Images)

"Republicans should have been more diligent in locating instances of individual corruption and handled those appropriately," said former representative Vin Weber (R-Minn.), an adviser to GOP leaders and the White House. "We did not need to lose all those seats."

The loss provoked the start of what could be a painful period of self-examination among Republicans eager to find answers, or place blame. With moderates in the Northeast falling, the Republican conference will grow more conservative. Some said they expect Speaker J. Dennis Hastert (Ill.) to step aside as party leader after the fallout from the page scandal and a new younger generation vowing to return to the promise and principles of the Gingrich revolution hopes to take the reins. Rep. Mike Pence (R-Ind.), one of several younger conservatives who has lashed out at his party's veering from core fiscal and social principles, is planning to run for leadership.

"It's not an affirmation of a Democratic agenda; I think that's clear, because they didn't offer one," said John Weaver, a strategist for Sen. John McCain (R-Ariz.). "It's about how we as Republicans set aside our principles to try to stay in power. We decided to try to spend money like Democrats, we decided not to reform or tackle big issues. And at the end of the day, the American voters said, 'Enough is enough.' "

The complexion of the Democratic presence in Congress will change as well. Party politics will be shaped by the resurgence of "Blue Dog" Democrats, who come mainly from the South and from rural districts in the Midwest and often vote like Republicans. Top Democrats such as Rep. Rahm Emanuel (Ill.) see these middle-of-the-road lawmakers as the future of the party in a nation that leans slightly right of center.

In private talks before the election, Emanuel and other top Democrats told their members they cannot allow the party's liberal wing to dominate the agenda next year. Democrats will hold 30 or 35 seats that went for Bush in the past, meaning that Democratic candidates such as Brad Ellsworth in rural Indiana are likely to face competitive races again in 2008. Still, their interests are likely to collide with those of veteran liberals such as Reps. Henry A. Waxman (Calif.) and John Conyers Jr., (Mich.), who will chair committees.

With that in mind, there is a chance the 110th Congress could begin on a bipartisan note. Democrats have vowed to move quickly to tighten ethics laws and require offsets for new spending -- two plans many Republicans will probably support in light of yesterday's results. Democrats also plan to push next year to raise the minimum wage, increase spending for cargo inspection at ports and reduce rates on student loans, all issues likely to draw some GOP support.

Partisan standoffs are likely over the war and any Democratic efforts to repeal Bush's tax cuts for upper-income America. In both cases, Democratic divisions could complicate Pelosi's plans. Democrats largely avoided detailed positions on a new Iraq strategy, but votes over spending for the military and the Iraq operation will force them to take a position.

At the center of all this will be Bush, who enters the final phase of his presidency with an opposition House and the sting of a campaign in which he was deemed to be an albatross. Bush arrived at Election Day with a lower approval rating than any other president in a midterm since Harry S. Truman in 1946. Aides took some consolation that the losses approximated the average for the sixth year of a two-term presidency.

For weeks, the White House maintained it was doing no contingency planning in case of Democratic gains. But Bush advisers are mapping out an agenda for his final two years that would include legislation that might win bipartisan support, such as extending and expanding the No Child Left Behind education program and creating a guest-worker program for illegal immigrants. Other priorities, such as adding investment accounts to Social Security, would seem virtually impossible in a Democratic House.

As the election approached, the White House said it would not trim its sails no matter who won. But as they absorbed the losses last night, Bush aides said he will return to his style of governance in Texas, when he forged a strong working relationship with a legislature led by conservative Democrats. "Obviously, we are disappointed with what happened in the House," said White House counselor Dan Bartlett. Bush, he added, will reach out to Democrats at a news conference today. "He will do his part."