President Trump, unlike a couple recent Presidents, seems to highly value both the Constitution and the 2nd Amendment. So, I don't believe he would ever do this.
The power of the President does not include the power to "ban assault weapons", anymore than it does to ban cars.
If Trump were to attempt this then I believe his political support would crumble and there is no way he could win a second term.
Q
Qanon # 919
Q !UW.yye1fxo ID: 5b7643 No.614101
Mar 10 2018 14:06:48 (EST)
Guns are safe.
Stop falling for FAKE NEWS.
Q
Qanon # 969
Q !xowAT4Z3VQ ID: 1a8912 No.815814
Mar 27 2018 23:42:33 (EST)
PARKLAND is a DISTRACTION.
PARKLAND was specifically organized & designed to DISTRACT [TEST] - watch the news.
ACTORS are ACTING.
FAKE.
NO POWER.
JUSTICE WILL BE SERVED TO THOSE PLAYING THE GAME [ALL].
GUNS ARE SAFE.
TRUST THE PLAN.
Q
“All warfare is deception”
I don’t think he would do it unilaterally but if the Senate were pressured to pass the House’s common sense gun control legislation then it would be all on him as to whether he would sign it or not.