A source who has seen recent polling, conducted by the Republican National Committee, told me the data show that a majority of Trump voters don’t believe the mountain of evidence that Democrats will win back the House in November.

By the numbers: 57% of strong Trump supporters believe it’s unlikely Democrats win the House, according to the source, who wasn’t authorized to share findings from the RNC poll with the media. (The survey of 800 registered voters — 480 via landline calls and 320 via cellphone calls — was conducted from Aug. 29 to Sept. 2 and has a margin of error of 3.5%.)

By contrast, election forecaster Nate Silver’s FiveThirtyEight website gives Democrats an 83.1% chance of winning control over the House.