Jim DeMint started the day back in, or at least considering going back in, to the presidential nomination race, but is now throwing cold water on the idea.
I wrote about it a bit over at Greg's place earlier in terms of the state of the GOP filed, but to add something about DeMint: at the beginning of the year, I gave him a pretty decent chance of winning the nomination. My first question this morning (when it looked as if he might get back in) was whether it was too late. As far as I know, we really don't know the answer to that kind of question.
I guess one way of thinking about it is that some of the important resources that one needs to win a presidential nomination are finite: important endorsements, party-linked money, experience campaign staff. Start late, and you lose out on resources that have already been allocated. Candidate time is another resource, and starting late fails to maximize that one (although DeMint has already done some campaigning and other things that candidates do, so he wouldn't be all that far behind.
But other resources are either essentially unlimited, or are so candidate-specific that early or late matters less. Rick Perry would presumably have access to money that no one who was not Texas Governor would be able to get to, for example. A candidate who has a positive national image (which DeMint doesn't; he's unknown) or strong relationships with important party groups (DeMint has those) prior to the campaign has a valuable resource that can basically buy off some days or weeks of campaign time.
I'm not aware of any effort to actually put all of this together empirically, but those are the sorts of things I'd want to put in the pot when I'm thinking about the disadvantages of getting into one of these things late. I'm really not sure how I feel about DeMint, had he stuck with his morning position and then actually entered the race in a few weeks. He definitely brings some advantages. As I said earlier, unlike Michele Bachmann and Herman Cain, DeMint is actually a conservative leader, not someone who just plays a conservative leader on TV. But it is getting late.