I can only think the Jared/Ivanka wing of the administration are behind this. His record on immigration was well known even before his name was floated. Bad choice.
The only nominee with a proven track record on immigration is Brett Kavanaugh. Amy Barrett might be OK, or might not. She's a big question mark in this area of law.
McConnell has told the NYT that he supports Kethledge and is trying to get President Trump to nominate him.
Kethledge is the favorite of McConnell and the Republican establishment.