“As President, Trump could issue an Executive Order banning all Federal Contract with Disney, including catering, services, visits, etc. “
Oh, there’s a lot he could do.
1. As you say, cut off any chance of government-related income for Disney.
2. Rigorous enforcement of presently-existing laws would make it very, very difficult for them or any company to continue these practices.
3. The bully pulpit works, publicly and privately. This was once called “jawboning”.
4. As President, he could make it clear to members of his party that they would be expected to do the same things on state and district levels, or national support might be difficult to come by.
You would be surprised at how much attention and traction he is getting on youth-oriented, usually flaming-liberal geek websites on this. Most geeks at least know people who have had these things happen to them.
The President sets the moral tone of the country. He cannot be ignored and always has the podium. The "bully pulpit" is one of the more significant powers of the presidency. Reagan understood this, as did many other presidents. It's clear Trump understands this as well and it's also clear he'll use it very effectively to advance his agenda.