On book tour in Ohio a few weeks ago, someone asked me if Donald Trump would finish out his term. The room was full of liberals and left-of-the-Democrats.

I pointed out that House Minority Leader Nancy Pelosi and other top Democrats have said that they have no interest in impeachment even if their party wins back Congress. I predicted—with the usual caveats about the perils of political prognostication—that Mr. Trump would not only finish his term but win re-election, due to the divisions within the Democratic Party.

Loud...