This is literally the first I'm hearing of this race; is Craig's name identification high enough to think this is anything other than a reaction against Whitmer and/or Democrats in general?
Craig's own internal has him down 1, so...
The bias of internal polling is that they're selectively released. Craig
released a poll showing him down one, which could mean he's sitting on a handful of polls with better results but wants to fundraise off "I NEED YOUR HELP TO BEAT GRETCHEN WHITMER" or something.
Not the most common tactic but it does happen somewhat often, especially this early in the race.