MICKEY KAUS: If there are two pro-amnesty nominees — especially if they are Jeb and Hillary — isn’t that a recipe for a third-party candidacy (which would probably threaten the GOP more than the Democrats)? Have the Republican donors backing Bush taken that into account? Plus: “As alert reader J. notes, the share of Americans who want more immigration has been holding steady — at 7%. Yet that 7% has captured the leadership of, not one party but both parties?”