ANSWER: You don’t. You concede the point and say “and?” Once you determine their stance is religious, you debate on legislating religious morality. Or, if the stance is secular, you debate the changing definition of murder within context of morals, values, and ethics.
If you do it any other way, you will miss the real issue. It is not about murder (they’re not obsessed w/ collateral deaths from war), or when life begins (no one can truthfully answer), or any of that mumbo jumbo. Their root is the culture war over religion vs secularism.
The only place you can go that MIGHT get through to them is to ask if they support every religion in influencing legislation or if they only want their flavor to do so - and then you’re where you should be, which is in a 1st Amendment debate.
