Before New York State politics was turned upside down and shaken all around today, we had noted that Hillary Clinton had hinted at the possibility of trying to woo Barack Obama’s pledged delegates over to her side. She also trotted out the neologism or seldom phrased “caucus delegates” in order to contrast to “pledged delegates.” But an old pal of mine gave me a call today that gave me an idea of something else that may be afoot here.

“Caucus delegates” are different from primary delegates. But not quite in the sense that people are saying. Not in the sense that they’re any less legit or meaningful than those produced by primaries. But they are less fixed.

Here’s what I mean. Caucuses rarely if at all vote directly for national convention delegates (I’m going to hedge here a bit because I don’t know the ins and outs of every states rules.) Generally speaking, they choose delegates to a state convention, which in turn chooses delegates to the national convention. In some states I think there are even intervening county conventions. But the key point is that unlike in primaries where the delegates really get picked on primary night, that’s not what happens with caucuses. When you have a caucus in state such-and-such and they say Obama got X number of delegates, that’s just an estimate. He doesn’t really have them yet. What it really means is that he got X number of delegates and if they all go to the state convention and vote for Obama then he’ll get the estimated number of delegates, or something very close to that number.

The point is that there’s a lot of potential haggling and funny-business possible between what’s actually set in stone now and what people are expecting come convention time. TPM Reader AO sent in this AP article from February which notes that back in 1984 Gary Hart actually lost delegates through the course of this sifting process.

In Nevada, Obama won 13 delegates and Clinton won 12. But if one side is unable to rally its supporters at any step along the way, it risks losing national delegates, much like Gary Hart did in 1984. Hart fared well in initial party caucuses when he ran for the Democratic nomination in 1984, only to see some of those delegates go to Walter Mondale at the state conventions, said Tad Devine, a Democratic strategist who counted delegates for Mondale.

People often ask me if national convention pledged delegates can switch candidates. And the answer is yes, they can. But in practice, it’s highly, highly unrealistic because the people who the candidate chooses to be their delegates are the staunchest of supporters, the absolute campaign true believers. So as long as that candidate is still in the race, the idea that they’re going to get wooed away is highly unrealistic.

But way down at the county convention level we’re talking really big numbers of delegates. You don’t know these people quite as well. Some of them may be new to politics. You’ve got to be certain they all show up at the different conventions. As the same AP article notes, if at any point one campaign or another can’t manage or control their delegates, they can lose some national delegates.

Don’t get me wrong. Hillary isn’t going to come out of Kansas with more delegates than Obama. Any changes would be small. But every little bit helps at this point. I heard twenty or thirty possible new delegates tossed around as a possibility today — a number that strikes me as a tall order. But I’ll defer to people who know more about the mechanics to decide whether that’s credible or not.

The key point to remember is that on balance, the party regulars tend to be Hillary supporters, at least disproportionately so. And they’re the ones most familiar with the process, possibly most likely to show (though that’s very debateable). On the other hand, it would be surprising if the Obama campaign which has proved so skillful at working caucuses would drop the ball in the subsequent stages of the process. It’s not the biggest part of the equation. But it’s another moving part you should have your eye on.

Late Update: This post at Daily Kos has some anecdotal evidence (of course unconfirmed) that some of this shaking out is already happening.