A number of people have written on the underlying facts here. The Jackson Clarion-Ledger (Mississippi) reported — but did not quote — that Falwell had endorsed Mitt Romney. The Boston Globe reported that Falwell denied this and that Romney denied saying it in the first place.
So all of this turns on the question of what was actually said. I got my hands on the quote. Here it is:
A number of religious leaders among the evangelical Christian community will validate my effort if I get in. A number will say they endorse me. Others will say that if I’m the nominee, they’d be happy to work for me. I think a few already have, Dr. Land and Jerry Falwell and some others said look if this guy’s the nominee, that’s great we’ll be happy to work with him.
In other words, it wasn’t an endorsement. Romney said that Falwell would "work with" Romney. Romney’s message is that he is, in some form, acceptable to some leaders in the Religious Right. For some, he will even be their first choice. But that he’s someone who can be worked with.
I think that Romney is selling this a little strongly. In the Globe article, Falwell said "could support" and in this quote Romney said "we’ll be happy". I think that Romney is definitely going beyond Falwell’s words here, as I believe the Globe article indicates.
In any case, I think that the whole point of this discussion is as a way of saying that the Mormon issue is not a show-stopper, which I totally agree with. So can we stop talking about the Mormon issue and talk about issues and politics and mechanics?