I remember around the time of the first immigration debacle in 2006 people were loudly debating the issue on the school bus and one hispanic kid said to another "Bush is on our side on this" and he said "Go Bush then!" I don't think Republicans were really so monolithic on immigration until the Tea Party came along which is probably why hispanics have tilted towards the Democrats.
I think the right simply let it go because the president had an R, kind of like how long much of the left has let go civil liberties under Obama just because he's a Democrat.