Nate Cohn would be surprised:
That doesn’t mean there aren’t costs to Republican shenanigans. A tea party-led shutdown would reinforce just about every reason why the public doesn’t like the Republican Party—that they’re extreme, unconcerned with real problems, and unwilling to compromise. That may not concern representatives running for reelection in safe districts, but it could matter in the Senate, where the GOP needs to beat Democratic incumbents, not just defend safe seats. The GOP’s image problem will make life more difficult for its eventual 2016 nominee. And with 28 percent of the time between Obama’s reelection and the 2016 Iowa caucuses now in the rearview mirror, the GOP can’t afford to reinforce and deepen its existing problems.
Trende downplays the electoral consequences:
The bottom line is this: The shutdown will probably not be a good thing for the GOP, and there’s a good chance Republicans won’t achieve their intended goal of limiting Obamacare’s reach. But at the same time, a lot of the prophecies of doom for Republicans are heavily overwrought. Unless things get too far out of control, the predictions of heavy GOP losses from a shutdown are likely overstated.