I have no doubt that the "terrorists" angle will work to whip up the Fox News crowd - it's a strategy no doubt designed to do just that, especially since McCain's numbers have started to lag again with the GOP base of late.
The real question is whether or not it will alienate the very voters that McCain needs to win, namely undecideds & independents. I question whether or not it is a useful strategy for reaching those folks, and I think it is very likely that it will actually backfire and repel more undecideds from McCain than it attracts.
So far it seems that Obama's campaign is responding swiftly and strongly to this latest broadside - their
"Erratic McCain" ad seems to be a very good pre-emptive counter-move. The fact that Obama is way ahead in the polls and has a strong, well-funded, and disciplined campaign is a big plus over Kerry when he got "swift-boated" in 2004. We'll see what happens.
ETA: I still maintain that, should the Dems go that route, the "Keating Five" charge against McCain will be far more damaging than this "terrorists" stuff against Obama. I say this because the average undecided voter will, I think, see the claim that Obama palls around with terrorists to be just too much of a reach. As I said, we'll see... but in the meantime, there's going to be a LOT of mud being slung around. Ugh.