That would be an outright treason charge and you'd see the President and swaths of officials face potential death penalties. With massive distrust in the government across the board, candidates like Ron Paul actually have a chance. Paul was never exactly liked for his politics by all his supporters but rather by his sincerity and perceived trustworthiness.
Alex Jones and cadre at 'Prison Planet' will toot their horns about being right about 9/11 and give credence to their other conspiracy theories about the Bohemian Grove, Income Tax scams, and police brutality all the way up until he tries to sabotage the Kyoto Accord and deny any form of climate change is real.
The Iraq War would end early and we'd be able to avert some of the recession problems connected to toxic unregulated bundled up debts. But if a libertarian is in charge, I really don't have the expertise to imagine how 2008 would have played out. My guess is that the 'too big to fall' would have actually fallen and we'd be in a potential depression before hopefully springing back stronger when smaller business rise to the occasion to fill the niches left behind.