Part of this, of course, is just dead-cat bounce -- people who were otherwise inclined to be behind him got shook up by the events of the late summer and early fall, and now that things have settled down they're feeling like maybe they overrreacted a little.
But the fact that they got shook shows they're shakable, and the fact that they didn't stay shook can be credited, I think, to the Democratic party, which with a few rare and honorable exceptions, refused to take advantage of the opportunity they were offered. What we got from most of them was the usual lame, mumbled yes-butnik pabulum. Now the train may be leaving the station, with the Dems standing rather foolishly on the platform -- as has been their historic role, save for a few short intervals, since they were on the losing side in the Civil War.