A lot of party activity comes down to meetings. One of my favorite writings on political parties is Joseph Lyford's short manuscript, Candidate. It's a description of the author's attempt to get the Democratic nomination for a congressional seat from Connecticut in 1958. A lot of the essay is a discussion of meetings Lyford had with party bosses, elected officials, and others. Most of those meetings were cordial, with Lyford asking for support, and the other person saying “I can’t support you right now.” In very few of those meetings did Lyford’s deportment make a bit of difference – the party leaders were already committed to another candidate. But Lyford still needed to ask – not doing so would have been a sign of disrespect.
I’m getting the impression that when party actors meet with a candidate they can’t support, it helps to have a reason why they can’t support him. For example, it was pretty obvious to everyone but John Kerry that John Kerry was not going to be the 2008 Democratic nominee. But how do you get that message into Kerry’s head? Well, enough donors and endorsers from 2004 have to tell him they won’t be there for him the next time around. But a one-on-one meeting with a senator can still be pretty intimidating, and Kerry will give you all these reasons why he’s improved as a candidate and why he should be supported again. So it helps for the donor/endorser to have some specific apostasy to bring up, so he can say, “John, I’d love to support you again, and I would, if it weren’t for X.” In Kerry’s case, X proved to be his botched joke about the troops. It was a stupid joke, and no one was going to back Kerry anyway, but that’s a convenient excuse for party actors. (Some evidence here.)
So, on the Republican side, how do we get to the point where the Big Three candidates drop out so the party leaders can back a Fred Thompson/Mike Huckabee type? Well, enough donors/endorsers have to meet with McCain, Giuliani, and Romney and say, “I’d love to support you, and I would, if it weren’t for X.” So what’s X in these cases? We’ve got some good ones in just the past few days. Somehow, I don’t think divorce will be the problem for Giuliani, since the GOP has ways of making amends with that, like they did for Reagan and Dole. (Although Giuliani has had more divorces than the entire Democratic field of candidates combined.) But there are plenty of Xs for McCain, a big one which arrived yesterday – he dissed the Club for Growth, accusing them of costing the GOP control of the Senate. And Romney managed a real doozy the other day when he quoted Castro in a speech to Cuban Americans. Schmuck.
I don’t know if these events quite rise to the level of Popkin’s gut rationality – they’re lower salience events that only the party hardcores are going to care about. But maybe that’s enough?