Religious reactionaries–the genuinely pro-life people–won’t make deals on the availability of abortion. Human life, in their eyes, is not negotiable. But they are willing to talk about beefing up the welfare state in order to make abortion less necessary. They won’t insist on it, mind you, but they are open to it.
The more secular reactionaries–the ones primarily motivated by racial, cultural, or economic grievances–dislike abortion because it empowers women and disrupts their traditional views about the leadership of society and the family. They are not genuinely pro-life. As a result, they have no interest in expanding the welfare state to improve the lot of involuntarily pregnant women (creating misery is the point, after all), but they see a national abortion ban as an obstacle to overcome in the overriding objective of winning power, so they are willing to compromise on it.
In other words, both sides are willing to make a deal on the issue the other side won’t put on the table. Since the religious reactionaries are a small minority within the GOP (just ask Mike Pence, who has now dropped out of the race), they are losing the argument within the party.