Well, they didn't say "no federal law". They just said no constitutional law.
But you are correct in the sense that the states are now free to legislate unless and until there is a federal statute. But if Congress does pass a statute, then that will override state law unless and until the Supreme Court strikes down the federal law.
Personally, I think a federal law is very unlikely. Even though something like 15 weeks probably has majority support, you'd never get beyond a filibuster because of the politics of the issue on both sides.
Well then I guess Tumpy ain't so ignorant after all, if federal law is possible... Albeit that it still would destroy the only long-term thing he can lay claim to.
As for me, I stand against returning it to the states - Though mildly, as I will take it as a win.
But the issue to me is one of approved sanctioning of death, which I think can only fall into two categories: Just cause (war), or Due Process (criminal conviction). I believe that flows outward from the Constitution, and it is therefore a Constitutional issue. In all other cases, I believe the Government is beholden to its original and default duty, the protection of Rights, first and foremost among them, necessarily Life.
So I do see it differently from most hereon.