No-one answered but the usual suspects sure did let me know how stupid I am without actually telling why.

Which organization would stop him? Congress does what Trump wants. And a lot of the seats there are in danger anyways so it would be in their own best interest.

FBI? Military? DoJ? Trump has already replaced top officials with his own men. So who exactly would march to White House and stop that? Yeah, there would be rallies, Democrats would be very vocal but Trump would just send the troops wherever he wants. He has already had a few test runs in Los Angeles and Washington.

So I would really like to know how this would be stopped. Hell, the way SCOTUS has acted they might actually eventually decide that what ever Trump did was perfectly in line with the Constitution and therefore legal.