The President doesn't write the bills, he can only pass them and submit them for consideration (which House/Senate have to approve, yadda yadda)
Congress doesn't enforce the bills, they can only try to pass them (which the President can veto, yadda yadda)
The Supreme Court neither write nor enforce the bills, they can only say whether they should be allowed or not.
So, the President can't do anything on his own, the Congress can't do anything on its own, and the Supreme Court can probably do the least on its own, but it's very good at saying "no" to the other branches.
That adds up to none of them having enough power to really get things booking in any one direction.