Liberals - just how stupid are they?

OK, so John McCain is a psychopath -- this we already knew. (What the "Bomb Iran" thing most reminds me of is Ronald Reagan's joke about "We begin bombing in five minutes.") But why is MoveOn.org buying airtime to point this out? McCain is struggling to convince Republican primary voters that he's not too liberal. An attack by MoveOn can only help him.

I can see three possibilities:
(a) MoveOn thinks McCain is the weakest of the Republican candidates, and they're trying to help him in the primaries so he'll be defeated by the Democratic candidate;
(b) MoveOn thinks McCain is likely to win the primaries (despite all signs to the contrary), and they're starting the general election campaign early;
(c) MoveOn is trying to raise money from a bunch of fucking idiots who don't understand how elections work.

Please vote in the comments, or let me know if I've missed something.