It’s next to a foregone conclusion that Republicans will score big gains in the 2010 elections. The question is: What does the GOP do then?

[IMGCAP(1)]Does it continue to just oppose and obstruct President Barack Obama and Congressional Democrats — or begin to show it can govern the country?

And the deeper question is: What is the Republican Party, anyway?

Is it a negative, narrow, exclusionist party of anger and grievance — the “tea party— party of Rush Limbaugh, Sarah Palin and Sen. Jim DeMint (S.C.)?

Or is it a positive, big-tent party with attractive new conservative ideas that might actually solve America’s problems — including a stagnant economy, growing inequality, enormous deficits, a world of danger and a flagging competitive position internationally?

That party would include, among others, former Speaker Newt Gingrich (Ga.), Rep. Paul Ryan (Wis.), Tennessee Sens. Lamar Alexander and Bob Corker, Sen. Lindsey Graham (S.C.), Indiana Gov. Mitch Daniels, Mississippi Gov. Haley Barbour, Louisiana Gov. Bobby Jindal, and, one hopes, 2012 presidential hopefuls Mitt Romney and Tim Pawlenty.

Consistent opposition to the agenda of Obama and the Democratic Congress clearly is working for now.

According to one of the GOP’s smartest analysts, former Rep. Tom Davis (Va.), “the midterms are really all about putting a check on Obama and the Democrats. The electorate fired Republicans in two straight elections and they’re not about to put us back in charge, but … voter anger now is going to be directed at the party that controls all the levers of power.—

The danger, he said, is that “particularly if Republicans take back the House, which is now a possibility, Obama can pivot like Bill Clinton did and become a very effective leader and win another term because we don’t know who we are yet except we’re not Obama.

“We’re just opposed to what they’re doing. We don’t have anything that people can rally around.—

Similarly, Democratic centrist Bill Galston of the Brookings Institution told me “the Republicans are now in a phase where their default is simply not good enough. It’s good enough to win Congressional seats.

“Being the party of grievance is a good short-term calculation if the guys with the ball are seen by the electorate to be fumbling it. But it does not prove that they are ready to govern.

“The only cure for that is a robust presidential nominating process because the new face of the Republican Party is not going to be hammered out at the Congressional level.

“So far, it’s obvious you have a bunch of right-wing populists who are mad as hell and aren’t going to take it any more. But beyond that, there’s nothing.—

Galston said he will be especially interested to read Romney’s new book, “No Apology: The Case for American Greatness,— out March 2, “presumably the opening gun in a multiyear effort to establish himself as not only a respectable figure, but someone who stands for something.—

When he began running for president in 2008, Romney actually presented a dynamic agenda for competing with China and India — for instance, giving green cards to foreign Ph.D.s and improving U.S. math and science education — but then was persuaded by aides to play to the hot-button crowd on immigration and social issues, forsaking his own economic expertise.

It isn’t really true that Congressional Republicans have no ideas for solving America’s problems. They just prefer to accentuate the negative.

Ryan, for instance, has produced a lengthy “Roadmap for America’s Future,— outlining Jack Kemp-ian free-market solutions for the economy, entitlements and health care. A new version will be out this spring.

He also proposed a consumer-based health care alternative and, as ranking member of the House Budget Committee, a GOP budget.

Ryan welcomes tea party adherents as part of the Republican coalition, but he says, “We can’t just be a party fueled by anger. We’ve got to be affirmative and optimistic and show how we can fulfill people’s hopes and aspirations — and we’ve got to be a big-tent party welcoming everybody who shares our principles.—

The party establishment tends to share the “big tent— view, but it’s opposed by ideological purifiers like DeMint, who famously said, “I’d rather have 30 Republicans in the Senate who really believe in limited government, free markets, free people, than to have 60 that don’t have a set of beliefs.—

Among other Republicans, Alexander has been an advocate of expanding nuclear power. Corker proposed an alternative to government takeover of auto companies. Daniels has made free-market health savings accounts work in Indiana.

With Obama’s approval ratings now below 50 percent, with Republicans leading in some generic polls and with unemployment high and holding, it’s possible Republicans just might have to help govern the country next year.

They had better start thinking about what they want to do — and talk about it, too.