'CNN did something extraordinary -- while Donald Trump was delivering his easily debunked lies, CNN fact-checked him in real time at the bottom of the screen. Given the scale of Trump’s mendacity and the stakes for the free world, it’s time that we go into the fall debates with a new rule — an instant fact-check on statements made by the candidates onstage. The Presidential Debate Commission should call out lies before the words hit the floor. Setting up a truth referee is not difficult. it ensures a reality foundation at a time when fact-free speech is the language of the political class.' Trump is surely the most compulsive liar to seek high office - the nonpartisan PolitiFact has rated 76 percent of his statements lies — 57% false or mostly false, and another 19 % “Pants on Fire” fabrications. Only 2 % of his assertions were rated true, and another 6% mostly true.'