In his jello brain this is a power play. He got some recent primary wins, so now he's going to dare Republicans to defy him on this under the threat of a future primary challenge. The next big election after the midterms will the presidential election where he imagines he'll be the kingmaker.

I agree I think it's unlikely enough people are going to bend on this, but with how spineless Republicans have been, it would not surprise me if a whole bunch of them started making noise about it. Jesters dancing for the king.