Who will drop out after tonight?

As we wait for the caucuses to get under way, the press are wondering who will leave the field after tonight’s results. This morning, The Politico reported that Senator turned actor Fred Thompson will drop out and endorse John McCain if he doesn’t finish third tonight. (The Thompson campaign has denied the report but Thompson was clear on TV this morning that he won’t stay in for the sake of it.)  On the Democrat side,Chris Dodd, a Senate veteran, has said he’s throwing in the towel if he doesn’t come in fourth.