Kethledge is so pro illegal immigration that he may be supportive of totally open borders. A very bad pick, if that come to be DJT’s choice - it wouldn’t be his first bad pick, but it could be the worst ever.
The GOPe doesn’t get to pick the nominee. Trump does, and as much as the GOPe are jackarses. They know, right now, that to defy Trump openly is political suicide. They will vote to confirm whoever the nominee is