If you have an issue with that, fine. But don't pretend to take the Constitution any more seriously than the Left does then.
Or is it ok to exceed the Constitutional mandate on things YOU agree with? How well does that work over the long run?
But the question you need to answer is whether a state could legalize murder, and still be within the Constitutional mandate to provide a republican form of government. I say “absolutely not.” In fact, I consider it silly to claim otherwise.