Single issue abortion voters made a lot more sense until they started voting for people in favor of separating children from their parents in cages.
That, and my also giant issue I have with them is a two folded argument of 1) They (generalizing of course) tend to not only be anti abortion, but anti contraceptive and sex education (ie anything that can be construed as promoting promiscuity) . Those two things are literally the two biggest tools in the kit to stop abortion (or at least significantly reduce it, and btw have. Look at abortion rates of South America vs Europe, it's night and day, and Europe is apparently full of godless heathens). The fact they can't ever get over that hump tells me they will never get what they want because you simply can't be that draconian and puritanical about it.
Secondly, many of them also literally also don't care about education, social services, health care, etc , plenty of things that would be "pro life" for those who are already alive. They are pro life but only if it fits what they think God wants. Not what is either a) practical to society or b) logically follow what their rhetoric means.