Burden of proof -- People who make factual claims are accountable for their words and should be able to provide evidence to back them up. We will try to verify their statements, but we believe the burden of proof is on the person making the statement.In practice this often means that if a person makes a statement and has no evidence to back it up, as with Harry Reid claiming that Mitt Romney paid no income taxes for 10 consecutive years by the account of an anonymous friend, then Harry Reid receives a rating along the lines of "Pants on Fire."
While it was extremely unlikely that Romney escaped income taxes for 10 straight years, part of the reasoning PolitiFact used in its judgment comes from the burden of proof fallacy (bold emphasis added):
Burden of Proof is a fallacy in which the burden of proof is placed on the wrong side. Another version occurs when a lack of evidence for side A is taken to be evidence for side B in cases in which the burden of proof actually rests on side B.Which brings us to PolitiFact's latest bending of its own rules. In rating a claim by Vice President Joe Biden, PolitiFact removed the burden of proof from Biden and placed it on Biden's target, Mitt Romney:
Biden said that under Romney’s tax plan "the average senior would have to pay $460 a year more in tax for their Social Security."When Biden moves to "fill in the blanks" he's making stuff up. Otherwise there's no blank to fill. Romney is not obligated to fill in the blanks, yet PolitiFact lets Biden skate essentially because Romney's failure to provide detail supposedly provides some justification for Biden making stuff up.
That figure is just one way to fill in the blanks in Romney’s largely unexplained tax proposal. It’s an average of a hypothetical, and it’s at odds with what Romney has said he’ll do, which is to protect deductions for the middle class and not raise taxes.
That's not fact checking, and it does not represent consistent adherence to PolitiFact's statement of principles. It adds another brick to the edifice indicating a liberal bias at PolitiFact.