The obvious worry about these physical confrontations is escalation. Groups of screaming protesters may just be exercising their First Amendment rights. Or, perhaps they have a James Hodgkinson among them. A nervous security detail might make the wrong assessment — as might a politician with a concealed carry permit. The slightest misstep in these situations could lead to tragic results.

A more political concern, however, is how utterly self-defeating these aggressive protests are. If blue mobs harass Republican politicians, how long until red mobs harass Democratic politicians? And if public officials are fair game, why not average citizens?

When it comes to the midterm elections, angry protests are a political loser for Democrats. The best thing going for Democratic candidates is the enthusiasm of their voters compared with indifferent Republicans. By making GOP voters feel under siege, progressive harassers are damaging their own chances in the fall.