One reason that video is cutting so deep today: The smug, fixed, chilly smile. That's not a teenager out of control. It's the familiar gleam of a zealot. Never in the history of this country has that look portended anything but bad news.

These marchers are, in a way, the inverse image of the Stoneman Douglas kids. Spending your high school years with Trump as President has many consequences. What we saw today--the belief that your cruelty, rage and entitlement are validated at the top--is one of the worst.

I know Trump doesn't have the decency to condemn those marchers and say "Don't do this in my name." But I thought for a while today that he might at least have the baseline political sense to do it. Then I realized: These are his sons.