Congress from both parties has been trying to figure out a political way to offer amnesty for over a decade. Now they have a President who is willing to take it upon his shoulders.
I would think that to people like McCain, Graham, Jeb Bush, and George W. Bush, Barack Obama's executive order is a literal godsend - not because of the political weapon it provides, but because of the amnesty it provides without them having to accept responsibility or blame. They can now just point to Obama and say that he's the one who did it. The Dems don't even have to go on record.