Washington ? Can this political marriage survive?

More than a half dozen tea party-backed candidates have captured Republican Senate nominations, and now the GOP is trying to bring their rebel supporters’ enthusiasm into the fold for November.

Republicans have little choice but to at least put on a show of unity: Alienating the antiestablishment tea party could undercut GOP efforts to post big Senate gains, perhaps even win control outright.

Judging by how quickly the GOP establishment embraced tea party nominees after earlier primaries in Kentucky, Colorado and Nevada, it may not take long for them to consider insurgent Christine O’Donnell one of their own in Delaware. The state’s Senate primary was the freshest source of Republican division after O’Donnell’s stunning upset of nine-term Rep. Mike Castle. He hasn’t yet rallied behind her but others have, including once and maybe future presidential candidate Mitt Romney.

And, after an initial curt reaction, Sen. John Cornyn’s committee to elect Senate Republicans made its support clear. “Let there be no mistake: The National Republican Senatorial Committee — and I personally as the committee’s chairman — strongly stand by all of our Republican nominees, including Christine O’Donnell in Delaware,” said the Texas lawmaker. He also sent her $42,000.

The message: The GOP has heard the tea party and is listening.

“Eventually you have to respect the will of the voters,” said Delaware’s Republican state auditor Tom Wagner, a longtime Castle friend who said the state GOP is still in shock. He said he’d campaign with O’Donnell.

It’s still not clear how soon — or even if — the state party will unify behind her.

Said a GOP House candidate who lost her primary, Michele Rollins: “We’re going to need a little bit of time to kind of settle down. It’s pretty shocking to Delaware, because we’ve never had an outside influence come in and dictate the result.”

But there are less than seven weeks to Election Day, and the out-of-power GOP can’t afford to turn off tea party voters who, if they turn out, could carry Republican candidates to victory in six or more Senate races, including Democratic-held states like Colorado, Nevada, Wisconsin, and Delaware. Republicans need to gain 10 seats to take control of the Senate, though even GOP advocates say that’s a steep climb.