I was thinking that there are four main scenarios with regard to the American economy and the GOP that could play out by 2012:
a) Stimulus package doesn't work, people blame Obama/Dems, throw 'em out.
b) Stimulus package doesn't work, but economy recovers a bit, Obama does a little "Morning in America" act and gets back in on his charm, Reagan '84 style.
c) Stimulus package doesn't work, but Dems sell themselves as the only people able to deal with this crisis, much like GOP did in '04 with the "war on terror" scare tactics, basically.
d) Stimulus works/economy recovers anyway, Dem landslide, GOP on the ropes for years.