Not against the first amendment. They paid to be there, they can still report on Obama all they want. They just cant be in the plane. Its like when you go to a club and get to drunk. You paid to get in, you get too drunk, they kick you out, but that doesn't mean you have to stop drinking?
So it doesn't have anything to do with the first amendment. I do think that's a little shisty though. I assume the Lady from Fox News is still there though, or has she vanished too?