1. Trump can't snap his fingers and build a wall. He isn't a dictator or a king. If there's anyone you should hold responsible it's the Republicans in Congress who refuse to allow him to do it. There are many things Congress could have done including the Nuclear Option and refused to do so.
2. Trump is no dictator or King. He can't snap his fingers and order Hillary's arrest. If his name was Kim Jong Un than perhaps he'd be able to. There is a process for that in a constitutional republic. It involves many factors along with a Justice department which as you well know is compromised. About all he can do is replace the leadership.
3. Trump hasn't signed any gun control laws passed by Congress.
4. As @redtail has said, he is looking for alternative ways to fund the wall with the Omibus Bill that he signed but didn't really want to sign.
Trump suggests US military foot the bill for border wall - CNNPolitics
If he can't do these things, why did he PROMISE them ?
Oh, that's right - to get my vote.
Never mind....