The dictatorship is now (by the courts) and any plan you come up with will be nullified (adjudicated) before you can institute it.
The problem with this approach is that she is trying to stop one branch's abuse of power by allowing the other two to abuse their own. Are you really prepared to grant this kind of power to the presidency when there's always the possibility that someone else like Clinton could come along? I don't want to risk that. And what kind of guarantee will you have even if no Clinton comes along that the order created by Coulter's solution would prevail in the future? There is none since her solution is extralegal.
What's stopping the court from overreaching when a wimpy executive comes into power? Or if a liberal president comes along who wants the court to usurp? And how is she really going to convince all the states in the union to ignore court rulings without provoking civil war?
There is no such protection under Coulter's idea.
There are better ways than the solution that Coulter offers such as passing an amendment barring the court from creating new law on any subject (not just marriage).
Or, Congress can limit the jurisdiction of the court.