If this is a Britt Internal, it's probably a lot closer, maybe Britt +4-6%. If Brooks makes the run-off, Trump will likely re-endorse him and that's GGs.
Brian Lewis theorized that the reason Trump un-endorsed Brooks is to put a fire under him and actually get him to campaign and it seems to be working.
I think Trump would probably re-endorse Brooks if he made the runoff.
But I don't think Trump was thinking that deeply about it. I think he just endorsed him because it looked like he was going to lose big and he didn't want to be embarassed.