Perhaps...

Depends on whether the demonization tactics bear more fruit than they have thus far.

The problem with McCain, for the GOP, is the problem we'll have if Clinton were to defy democracy and be selected for the nod:

People just aren't sure they'll be much better than the opposition.

When it's hard for an individual to decipher which candidate they see as the lesser of two evils, they're not likely to vote.

McCain carries a lot of Bush's baggage, and I'm not sure even the best smear campaign will relieve that inheritance.