If men got pregnant, every single person would sympathize for them. They would get everything handed to them. They would lay around and act like they're royalty. If they didn't want the kid, they'd kill it. Simple as that. They wouldn't care. It would be a common thing to them.
With the number of men currently holding positions of power, it would pretty much immediately mean that the current abortion laws on the books would have immediate changes made to grant either special circumstance, loosen the regulations that might declare when a pregnancy is "high risk", and its a safe bet any forced ultrasounds viewings would be immediately nixed.
Hypothetically, men would be held accountable for their pregnancy as unequally as they are held accountable work women's pregnancies today. They have zero say in present day pregnancies and child support/time sharing agreements ... I don't see them gaining any more rights just because they bore them.
That might be because of the current natural order though. Guys having the kids also would be a completely different dynamic. I suppose both parents would have a bit more of an equal say and the one who actually bears the child would be up to chance?
Unless the guy's raising a xenomorph, I don't think that a male abortion would be legalized. Where would a baby form anyway? Would it be a parasitic embryo? A badly written fanfic by a 14 year-old teenage girl new to this whole "sexuality" thing? Would somebody have picked "Option D: Stick it in"? How that baby got IN there is what I'd worry about.
So I don't see how men becoming pregnant would change all men to become pro-choice. I know that personally if I got raped by a female, and became pregnant, I would not abort the homosapien. The unborn homosapien didn't get to chose that its mother raped its father, and it shouldn't die because of that either. Besides it isn't a part of my body, an unborn homosapien has its own cells that are different from my own. So me aborting it would be killing something that is a separate organism from me. I effectively would be murdering (definition that means to destroy or end) a human. Could I live with the fact that if it wasn't aborted it could experience the full potential of life. My only fear would be the pain since I am personally a wimp, of course what is a temporary pain to saving the existence of a human life.
Conservatives do not hold the belief that abortion is wrong simply based on the gender of the person receiving it but because they think that it is murder. If men were the sex that carried the child the belief that it was murder would be unaffected. You know that there are women conservatives right? Women who think abortion is wrong?