The POTUS doesn't really have a lot of power and that's how the FF wanted it.
However he can use his pen and write executive orders which go around Congress.
And if his EO's are nothing more than an end run around congress, the next the other-party-potus will just undo them ... which leaves the originator without a legacy.
Yup. And you can bet your ass that's just what he's going to do.
The only legacy that douchebag will have is how bad a POTUS he was.