That would be cool if the Supreme Court ruled after Trump and the Republicans passed a federal law making abortion illegal and equal to murder, that they could not do that. That it was a states rights issue. I hope you are right.The USSC just ruled that the issue of authority to decide the legality of abortion shall be left to the states to decide since the right to the an abortion is not granted in the Constitution.
As such, this hypothetical ban your are speaking of would be unconstitutional.