I found myself seated at my computer last month, watching on YouTube the comedian Bill Maher talk about Donald Trump’s marriage. If you don’t share Mr. Maher’s politics, you are likely to find him an odious, even loathsome character, for he doesn’t really exist outside politics. His standard tone is mockery, his modus operandi to lacerate his targets with obscenities, flash a nervous smile, and then bask in applause from his audience.

I was watching Mr. Maher on YouTube to see how far he would go on the subject of the Trump...