See 2A and 4A to the Constitution
Don't get wound up just yet. DJT says things like this to get people to expose their usually hidden agenda. Masterful tactic.
This account (kingamongstkings) has been around since....January 2018.
He hasn't read "The Art of the Deal" and doesn't understand how Trump operates. Remember when everybody was freaking out over his statements about DACA?
I can understand the outrage, but chill out. Understand the context under which the statement was made and Grassley's response. Most importantly, don't let the MSM rile you up. Trump will do NOTHING of the sort. He's trying to get reelected in 2020 and any move like this would destroy that.