From a Washington Examiner column by Byron York:

In the new book “Russian Roulette,” authors Michael Isikoff and David Corn note that Christopher Steele, the former British spy who wrote the (Trump) dossier, once said there was perhaps a 50-50 chance of the Moscow sex episode being true. Glenn Simpson, head of the opposition research company Fusion GPS, which commissioned the dossier, reportedly considered the Russian source for the story a “big talker” who might have made it up to impress Steele.

But now, some leading lights in the political conversation defend the dossier by arguing that it has not been proven untrue — as if that, instead of proof of truth, were the standard to apply to such consequential allegations.

“Setting aside the absurd and patently unfair ‘guilty until proven innocent’ standard that thinking requires, it also ignores the fact that the FBI has never tried to disprove it,” Republican Rep. John Ratcliffe, a former federal prosecutor who now serves on the House Judiciary Committee, said in a recent text exchange. “When the president asked the FBI to do exactly that, one of Jim Comey’s secret memos documents the response: (Comey) told him it is ‘very difficult to disprove a lie.’”

Yes, it is. And that’s something to keep in mind whenever someone suggests the dossier is worthwhile because it hasn’t been proven false.