Democrats just can’t quit Donald Trump

For the first time in a long time, Democrats have a presidential nominee in Kamala Harris they are excited about. But they can’t quit Donald Trump. The party’s muscle memory and strategic imperative for bashing him are too strong.

And so, in the opening days of the Democratic National Convention here, this celebration of Harris has turned into a bludgeoning of the former president.

“Until we defeat Trumpism there’s nothing else that really, really matters,” Rep. Ro Khanna of California told reporters after a delegate breakfast on Tuesday. “And if we don’t...