This. This is very important: the necessity to seem "non-partisan" for those sites makes it wayyy too easy for the liars. After all, if you get to lie all the time and the "fact checkers" feel compelled to scrutinise your opponents extra-hard just so they can say that both sides have about the same lying rate, it's win-win!

There are issues where there are two sides. But more and more, people fight over _facts_ and this means that one side is right and the other wrong, and if you claim otherwise, you are delusional. There is no middle ground to the debate on the shape of the planet. If you say that gay parents cannot raise a child, this is a statement of fact, not an opinion. If you tell me there is no global warming, this is a statement of fact, not an opinion. If you tell me that the gold standard is a good idea, this is a statement of fact, that reducing taxes will increase revenues, and so on, and so forth.

All things amenable to experimental verification -- and in many case which have been previously experimentally checked -- should not be debated. Journalists should just mock the politicians saying stuff which is obviously false.