And they'll be stepping on each other's toes even after the music stops:
Some on the right pushed for using must-pass spending legislation to try to shut-down Obama's move. One lawmaker— two-term Republican Rep. Mo Brooks of Alabama — raised the specter of impeachment. Party leaders warned against such talk and sought to avoid spending-bill tactics that could lead to a government shutdown. They said such moves could backfire, alienating Hispanic voters and others.
In a closed-door meeting with Senate Republicans, McConnell urged restraint. Still, there were concerns among some Republicans that the potential 2016 presidential candidates in the Senate would use the announcement to elevate their standing, challenging Obama directly.
Good luck on that whole "restraint" thing. Even if Republican leaders actually want their flock to behave like adults, which is not a foregone conclusion, the tantrums associated with this Executive Action will be legendary. I doubt we'll be lucky enough to see any Buddhist monk-styled immolation in the aisles of Congress, but there could be some tears of frustration. In actuality, it won't be a "groundbreaking" move by the President: