Subject: "We took freedom of speech away"
And here's Trump's rationale: burning the flag incites people to fight, therefore flag burning is not protected speech.

“…a flag burning mob, and we’ve uh made it uh one year penalty for inciting riots. we took the freedom of speech away because it’s been through the courts, and the courts said ‘you have freedom of speech’ but that— what has happened is when they burn a flag, it agitates and irritates crowds, they’ve never seen anything like it, both sides, and you end up with riots, so we’re going on that basis, we’re looking at it from not from the freedom of speech, which I always felt strongly about, but never passed the courts.”

Trump figuratively uses the Constitution as asswipe, but that's OK. Burn a flag, get a year in prison.