This idea that America might hiccup and suddenly become a socialist state without duly concerned citizens having a say so is hilarious. From an outsiders point of view your choice of candidates is right wing Obama or right wing McCain, the difference politically between them is hardly worth mentioning when you compare them to true left wing politicians.
It is a little surprising that otherwise intelligent and articulate people are taken in by these ridiculous press slander campaigns, and believe without question that a little more tax from rich people = decline in to a Stalinist dictatorship. For a start there are plenty of socialist countries that are doing just fine and have been doing fine for a long time, without the 'inevitable slide in to communism' being a problem. This laughable fear of anything more left wing than your Democrats (who by anyone elses standards are right wing) is a bit outdated now, the Cold War ended a long time ago! All it seems to be doing is distracting voters from actual politics.