It’s always amazed me how little American conservatives seem to respect or know about the history of the country they claim to love.

“Whether the performance of an induced abortion is sinful we are not agreed, but about the necessity of it and permissibility for it under certain circumstances we are in accord.“ --a 1968 statement by a group of prominent evangelical leaders.

So yes, abortion has long been a subject of debate and contestation within American Protestantism. There are currently many pro-choice pastors of many different denominations, and in the past there were even more such folks. Those facts don't care about Ben's feelings.

If you, unlike Ben, are interested in actually learning something about the history of the pro-life movement in the US rather than demagoguing about it, here's a good place to start. https://www.oah.org/tah/issues/2016/november/abolishing-abortion-the-history-of-the-pro-life-movement-in-america/

It's not that hard to make the "conservative" case for pro-choice
a) What a woman does with her body is none of the government's business.
b) The Enlightenment-informed founders thought that using theology to guide state policy is bad for both religion and the state.

Don't think abortion is right? Don't get one.
Think abortion is a sin? Then don't get one, and let each person work that question of sin out between themselves and their own understanding of God.

This is just basic, conservative logic, applied to the issue of abortion.