Ever since I read it, I’ve been fascinated by the line in National Review’s endorsement of Mitt Romney which said “Our guiding principle has always been to select the most conservative viable candidate.”
I wouldn’t deny that progressives are prone to a certain amount of tribalism in our internal deliberations, but that kind of explicit ideological maximalism closes off debates on the merits in a weird kind of way. And not only do you see much more ideological maximalism in conservative media, but conservative media is a much more influential force than progressive media. This makes it extremely difficult for arguments on the merits to get off the ground which, in turn, makes it hard to mount persuasive arguments against candidates who you think may be wrong on the merits.
That's true. Liberals have both a strong progressive wing and a more centrist neoliberal/third-way wing. And these two wings fight a lot because they don't really like each other very much. But in the end, they're both genuinely influential. They really do act as countervailing forces to each other within the halls of the Democratic Party.
But Republicans? There's the tea party wing and that's about it. Sure, you've still got a few Bruce Bartletts, Ross Douthats, and David Frums roaming around, but they've basically been excommunicated from the party. For the moment anyway, they have no influence at all. Ditto for the old guard from the George H.W. Bush era, who mostly just keep quiet these days.
Anyway, there's nothing original here. But it's still worth repeating once in a while. The Republican Party and the Tea Party are pretty much one and the same now.