Todd Akin is not going to be the next senator from Missouri.

There’s plenty we still don’t know about how the Akin affair is going to turn out, but that much we know. Oh, it’s not 100 percent; there’s always some uncertainty in politics. But it’s now highly unlikely. Democratic Sen. Claire McCaskill isn’t very popular, and Akin went on Mike Huckabee’s radio show again today to say he’s going to stay in the race, but it doesn’t matter; he’s finished. Given that almost every prominent Republican of note, from Mitt Romney to Rush Limbaugh on down, has furnished quotes that would make for absolutelydevastating TV ads, there’s just no way for the Republican Party to back down.

Moreover, I suspect that Akin will not reap a huge fundraising bonanza from all the publicity. Some, certainly — but too much of the potential money is party money, and it’s not going to show up as long as Republican leaders keep giving cues to shun him.

In most nations, the party would simply replace him. But the U.S. system gives individual candidates a bit more leverage; in particular, there’s no one who can force Akin off the ballot if he wants to stay on. It’s certainly possible he’ll do so.

I suspect, however, that Greg Sargent is right and that Akin will eventually choose to get out. The first overnight polling didn’t show any apparent collapse, but those were taken before many Republicans had spoken. Within a couple of weeks, if Akin lasts that long, it’s going to be obvious to everyone that he’s going nowhere. It comes down to this: We can never know what’s going on inside a politician’s head. All we can do is calculate the incentives politicians are faced with. And all the incentives right now are for Akin to give it up.