The mood at the Americans for Tax Reform party last night in downtown Washington was ebullient. It's a "slaughter" Ralph Reed announced as he leaned over to pluck a grape from the buffet table. Conservatives, young and old, congregated to celebrate. David Keane, head of the American Conservative Union, told Sam Tanenhaus of the New York Times that this was an even more significant victory than 1994 because of a new Republican dominance in the state legislatures. Grover Norquist pointed out to me that all that's left for President Obama is to become a "foreign policy president."

But now that it's won the House, the GOP could face a crisis of identity question. Will it attempt to rollback the entire Obama agenda? Or will it proceed more cautiously? The question is well-framed by Ari Fleischer in the Wall Street Journal. According to Fleischer,

No one knows what will happen when these two approaches collide inside the Republican caucus. It will be a major test for Mr. Boehner and likely Majority Leader Eric Cantor (R., Va.) to resolve this coming clash. My advice to the leadership: Freeze domestic spending at 2008 pre-crash rates; vote on deeper spending cuts for several domestic spending programs, even if there aren't the votes to win; and steer clear of entitlement reform unless the president goes first.

My advice to the tea party freshmen: Slow the galloping horses to a trot. Big government was built over decades; it can't be dismantled in a year, especially when Democrats control the White House. If Republicans push too hard, we may blow our chances to actually reform entitlements and meaningfully roll back the size of government after the 2012 elections.

The Tea Party types may well be feeling frisky. But it's also the case that this election may resemble the 1966 midterm election when Republican centrists were elected. This election could prove the same. Pat Toomey of Pennsylvania is a staunch advocate of free-market economics and member of the Club for Growth--very different from Christine O'Donnell and Sharron Angle, both of whom were repudiated at the polls. Republicans will aim to extend the Bush tax cuts, reform the inheritance tax, and push for entitlement reforms. How President Obama reacts to the Republican victory is also an open question.

His party has moved to the left. Many of the blue dog Democrats were defeated. It's now his Democratic party. He has to try to rebuild it. But the only way he can do so is by trying to reach compromises with the Republican House.

The polls indicate that voters trust neither party. The real problem remains the one that Richard Nixon and Henry Kissinger diagnosed in the early 1970s. American may well be a declining power that has to husband its resources. A country with diminished resources cannot continue to support extravagant commitments abroad and at home. As John Judis observes in the New Republic,

if I am right about the fundamental problems that this nation suffers from at home and overseas, then any politician’s or political party’s victory is likely to prove short-lived. If you want to imagine what American politics will be like, think about Japan. Japan had a remarkably stable leadership from the end of World War II until their bubble burst in the 1990s. As the country has stumbled over the last two decades, unable finally to extricate from its slump, it has suffered through a rapid of succession of leaders, several of whom, like Obama, have stirred hopes of renewal and reform, only to create disillusionment and despair within the electorate.

The difference between previous economic crises and this one is that America is now wholly indebted to China. Competition from abroad is becoming keener. In the past America could continue to act as a profligate power. Can it continue to do so?

For now, however, the GOP has successfully mounted a surge against Obama. Whether it needs to have a concrete program is a question mark--running against Obama, and his attempt to reinvent America on European Social-Democratic lines, may well be enough. It's not as though the welfare state, which Britain is trying to dismantle under David Cameron, has won such high flying marks in Europe. The Tea Party has won the rhetorical debate by framing it around the idea of American nationhood and individuality as opposed to an omnicompetent state.

Obama is in trouble. By capturing ten new Governorships, the GOP has severely compounded his reelection difficulties. And it has exposed him as too liberal for much of the country. The aloof and cerebral president will have to reinvent himself. Otherwise, he'll discover that the Republican midterm victory was simply a dress rehearsal for the big one in 2012.