This is one of the logical fallacies. The list of fallacies is one of the few things I retained from a one semester liberal arts elective named "Logic". Fallacies are, however, something everyone should be aware of because almost every argument the Left makes is full of them. Ad Baculum was recently demonstrated by the union thugs in Michigan. Other favorites are Appeal to Emotion or Argumentum ad Hominem. Here's a good summary.
You could even start a drinking game - chug a beer every time you recognize a fallacy in one of Obama's speeches.