He can't keep his story straight because he screwed up the first time 'round. Refusing to even consider the nominee was stupid. The GOP could have held their hole cards secret and spent the months between now and the election bashing the crap out of the nominee. Some Senator could have even stood on the steps of the Senate and given a little speech about "Garland's America" and how we'll all be disarmed and the government will decide what we get to say if he gets appointed to the Supreme Court.

But the GOP is stupid, and when they realize they've stepped on their dicks they have to make nearly-as-stupid corrections.