Do they believe their own rhetoric?

I've been doing a little thinking (rare event) about the Republican's over the top claims about the evil Democrats supporting terrorism. "A vote for Democrats is a vote for terrorism." What starts to worry me is that Bush & Co. may really begin to believe their own rhetoric. This may not only rile up the "base," it may rile up the rilers as well. So, the question is, how big a step is it from saying and believing "Democrats support terrorism" to saying "Democrats should be arrested as terrorists?" With Bush's new powers, what's to stop him?