He's trying to fool one side or the other but he is only winning the people who don't care.
You want strategy? How's this for a strategy? Every time he's asked about abortion, he should immediately start talking about "compulsory abortion" and how far more people in this world are living in oppressive places with "compulsory abortion" (aka "one child policy") than are living in places where abortion is illegal. He should point out the trend that many political, academic and economic elites favor compulsory abortion and crave it among their highest utopian eugenic policy objectives. He should say he's going to do everything in his power to make sure that "compulsory abortion" and "compulsory euthanasia" for B.S. pretenses like "saving the planet" or "affordable healthcare" are explicitly unconstitutional and are therefore impossible in the United States of America.
He should NEVER use weasel terms like "personal or religious beliefs" or "reproductive freedom" when he's discussing abortion.
And speaking of “compulsory abortion”, the camels’ nose is under the tent via Obamacare where we are all forced to pay for murderous child sacrifice. And the few who say so are not saying it enough!
To stop him, you have to win at the ballot box. It's not enough to stand up for principle.