On either end of Pennsylvania Avenue, the political incentives are shifting at the start of a second Bush administration - and with them, prospects for everything from Social Security and tax reform to the future of the GOP.
For President Bush, the aim is no longer to win reelection but to consolidate the gains of the first term and establish a legacy.
But for Republicans on Capitol Hill, the imperative to back their president going into an election - a leading factor in muscling major changes in education and Medicare over the top in the first term - is no longer a factor. This president cannot run again. Nor, in a rare break from tradition, is the vice president on track to take his place.
So, although the president starts his second term with an advantage few other two-termers have had - a Congress controlled by his own party - ideological kinship among Republicans could be tested by a new battle over GOP direction and leadership in 2008 and beyond.
"The Republicans had a great incentive in the first term to position him as a successful incumbent. He's going to have it tougher this time," says George Edwards, director of the Center for Presidential Studies at Texas A&M University in College Station.
The scope of the new challenge to hold Republicans in line surfaced early in last month's lame-duck session of Congress, when 67 House Republicans broke with the White House and their own party leaders on intelligence reform. The GOP rebels said the plan did not go for enough to curb illegal immigration, an issue they want revived early in the 109th Congress.
In a bid to firm up Republican ranks, House GOP leaders sent a message to restive colleagues after that Dec. 7 vote by stripping Rep. Christopher Smith (R) of New Jersey of his gavel. As chair of the Veterans' Affairs Committee, he had pushed increased spending for veterans at a time when House leaders urged restraint.
While Republicans want the president to be successful, they are also voting with an eye to coming elections, starting in 2006. And unlike most elections with an incumbent president, the vice president is not a de facto presidential front-runner.
"There will be a lot of people jockeying for the presidential and vice presidential nomination. For some, that will mean cleaving very tightly to Bush; for others, it means moving away from Bush. It's not unifying," says Alan Brinkley, historian and provost at Columbia University.
Moreover, President Bush begins his second term with only a 53 percent approval rating - the lowest of any second-term president since World War II. Most Americans said the war in Iraq had been a mistake, and 65 percent said he did not have a mandate to reform Social Security, according to a University of Pennsylvania/Annenberg survey released this week.
To consolidate the victories of his first term, President Bush must still engineer a successful endgame in Iraq, quell a nationwide backlash over the tougher federal requirements in his signature No Child Left Behind Act, and, possibly, address a growing fiscal crisis in the newly expanded Medicare system - at the risk of reopening rifts within the GOP.
"Republicans have such a big majority now that a lot of the fights are going to be within the Republican Party. The challenge will be to hold the team together," says Stephen Moore, a conservative activist and president of the Free Enterprise Fund.
For conservative Republicans, who vigorously opposed President Clinton's bid to expand the federal role in the education, the vote to support Bush's even more ambitious No Child Left Behind Act was a tough one. So was the vote to expand Medicare entitlements to include a prescription-drug benefit, a bid that 25 House Republicans opposed in 2003.
Still, activists say that the array of new issues the president is proposing for his second term, including an overhaul of Social Security, capping lawsuit damages, and extending tax cuts, is far less polarizing within the party.
"When you look at what the president has identified as his top priorities, they're items at the top of what the [conservative] movement is wildly enthused about, such as Social Security reform. We're almost equally passionate on tax reform and tort reform," says former GOP Rep. Pat Toomey, the new head of the Club for Growth, a leading conservative group. Mr. Toomey was one of the GOP House members who broke with Bush on the 2003 Medicare vote.
In fact, those expectations could risk being too high, other activists say. This week, social conservatives took issue with the president for comments to the press that he will not aggressively push a constitutional amendment banning same-sex marriage. "Because conservatives invested so heavily in this past election in Bush and the House and Senate, there are extremely high expectations among conservatives [for] policy victories," says Mr. Moore. "It will be very difficult for Republicans to come close to matching those."
Many Republicans are keeping their distance from the Social Security fight, once viewed as the "third rail" of American politics. GOP lawmakers are divided on how to pay for new private accounts. Sen. Lindsey Graham (R) of South Carolina and Rep. Jim Kolbe (R) of Arizona are calling for spending cuts or even tax increases to pay for the overhaul. Tax hikes won't fly with most House conservatives.