Obviously the landscape will be different in 2012. But different how? On the one hand, the GOP has lurched sharply right, and activists will interpret the inevitable gains as a vindication of that strategy. On the other hand, if Republicans blow a few races because they nominated Sharron Angle type candidates, the message may filter down to the base that always nominating a purist conservative is not a cost-free approach.I think it would take quite a reversal -- not impossible, but not likely -- for Republican activists to learn that message from 2010. Let's see...we have purist candidates nominated in contested primaries in KY, UT, NV, FL and AK; depending on how you read it in CO and WI; and perhaps in DE and NH. One (in Utah) is certain to be elected. Suppose that purist candidates cost Republicans two or three Senate seats (about the maximum plausible number). If it turns out to be a good or a very good year for Republicans, they're going to believe that everything they did was electorally smart -- sure, they'll say if pressed, we might have added Delaware if Castle had been nominated, but he wouldn't have voted with us anyway and besides we won a landslide, so why are you questioning our strategy? On the other hand, if things go the Dems way, odds are that for every Rand Paul who loses there will also be a Carly Fiorina and a Dino Rossi who also lost, and it won't be obvious at all to Tea Partiers that extremist candidates were responsible. No, what it will take will be a less-than-expected win for Republicans (so they're looking for an explanation of failure, not success) combined with very selective losses by purist candidates. Remember, in general elections candidates are hardly the only important factor -- they matter, especially at the extremes, but they're not as important as, say, the partisan composition of the electorate. So it's likely that some of the GOP purists will win even if they aren't nearly as strong general election candidates as those they defeated in the primaries would have been.
So what could save Olympia Snowe? It's possible that in 2012 activists will be focused on a presidential nomination battle and will put less energy into Congressional primaries. And, of course, you can't beat something with nothing; it's always possible that she just won't draw an opponent. It's also possible that, even though Chait is surely correct to say he can't "see how her ideological bona fides could possibly be solid enough to withstand a real primary challenge," that perhaps with a two-year head start it's possible for an incumbent to build personal relationships with conservatives strong enough to get them to ignore ideological deviations. Possible, but I wouldn't want to stake my career on it. On the other hand, it's not as if the latest examples of party-switching have worked out all that well (just ask Arlen Specter). Of course, it's a long time from now, and all sorts of unpredictable changes could happen, but it's hard to see a lot of good options available right now for Snowe if she wants to stay in the Senate beyond 2012.