[Herman Cain] has good chance of having some influence on the race — perhaps like Mike Huckabee in 2008, a candidate with whom he shares some similarities. And I don’t think the possibility that he could actually win the nomination can so easily be dismissed. The argument that you’re likely to hear elsewhere is that candidates without an electoral track record haven’t won the nomination in the modern (post-1972) primary era. But it’s a small sample size, and some or another precedent is broken in nearly every election cycle.I'm going to spend a little time on this, because it gets at several important things about the process. First, to Silver's credit, he's right about one thing: finding simple patterns in the postreform era is a dangerous game. Indeed, it's a bit worse than he suggests. Reform took place between 1968 and 1972, which would give us twenty trials: 1972-2008, two parties per cycle. But for most questions we can probably ignore "contests" with an incumbent president seeking renomination, which knocks out half of the GOP examples and two from the Democrats. Moreover, the evidence suggests that the early cycles after reform were different in important ways, so for many questions I wouldn't use cases older than 1984.
As far as Cain, however...the point isn't really that "candidates without an electoral track record haven't won the nomination." It's that they haven't really come close. The best showings by candidates who hadn't been elected to anything were, if I recall correctly, Jesse Jackson's campaigns in 1984 and 1988; Steve Forbes in 1996 and 2000; and Pat Buchanan in 1996 (and, I suppose, 1992). I certainly wouldn't count Wes Clark's 2004 campaign; military heroes, of course, have a long history of winning nominations. I suppose Pat Robertson in 1988, too.
Not only did Jackson, Forbes, Robertson and Buchanan never get particularly close to winning, but none of them is really a good comp for Cain. Jackson was a national figure, and a leader of an important constituency within the Democratic Party, long before running for president. Robertson was basically similar. Buchanan was well-known, and had worked in two White Houses. Forbes is perhaps a closer fit, but he had instant name recognition, if nothing else. Cain has none of that.
The larger idea here has to do with what a nomination process is really all about. Josh Putnam makes the point today: "The party decides these things -- more often than not." Or to put it another way, it's a mistake to think about presidential nominations as elections between equally matched candidates appealing to mass electorates. Instead, then of it as a political party -- which is a sprawling, unorganized combination of people and organizations -- trying to make a decision. That might involve resolving conflict, or it may just be a question of coordination in a system that has evolved (partially because of the way we regulate political action, and partially for random historical reasons) to make coordination very difficult.
So, yes, it's very easy for obscure candidates who have no real chance to have a couple of good weeks. Or, for that matter, famous candidates -- Bachmann, Gingrich, even Donald Trump -- who have no real chance to have a couple of good weeks. The sorts of things that push the process along in the long run don't really have much effect on short-term bubbles long before the voting starts; they don't even, always, prevent no-chance candidates from winning the occasional primary or caucus. The people who determine nominations don't care much if Pat Robertson finishes 2nd in Iowa or if Jerry Brown wins a late-season primary in 1992. But when they actually choose, that's not what it's about. Now, I don't want to make it sound like a handful of people in a back room -- there are a lot of people involved who matter, including activists, and they don't always agree. So conflict can be a real part of it. However, it's just not going to be about who focus groups like after a debate -- it's not going to be an unmediated contest with candidates on the one side and independent, autonomous voters on the other. It's a party decision, and there's no reason at all to think that the Republican Party would choose Cain.