Double negative = A syntactic construction in which two negative words are used in the same clause to express a single negation.
E.g. If President Trump had said there's no reason it wouldn't not be Russia that hacked our election, it would have been a double negative.
Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of “high crimes & misdemeanors.” It was nothing short of treasonous. Not only were Trump’s comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???