Number One: Ignore any facts that don't fit your lies and falsehoods. If you do stumble over a fact that shows your position is absurd, use a strawman argument or even better, go for the old argumentum ad hominem against your opponent who brought up the inconvenient fact.
Number Two: Say it's all the Republicans fault (or libertarians, right-wingers, tea partiers, Ron Paul).
Number Three: Call your opponent a racist (and if they think Lincoln was a tyrant and the South was right to secede from the Union and the War for Southern Independence was a right and just cause, say they support slavery).
When all else fails, just tell the person with the facts on their side to go fuck themselves.