People aren’t “pro-abortion” they are pro-choice.
And it’s an issue of bodily ownership. Who owns your body – you, or the state? If you do then the state cannot, morally, put you to death any more than it can force you to undergo any medical procedure. The state may confine you, it may restrict your ability to move about in society, but it cannot claim any moral basis for the authority to terminate your life.
Likewise, the state cannot claim any moral basis to force a woman to carry a pregnancy to term anymore than it could force a person to host a cancerous tumor.
If the state can terminate your life at its whim, or can force you to undergo any procedure, or make you carry within you anything you do not wish, then the state, not you, owns your body. And if you do not have ownership over your own body, if you are not sovereign over your own flesh, blood and tissue, then what rights do you truly have? Bodily autonomy is the most basic, most fundamental right there is.
It is on this basis, bodily autonomy, that I oppose the death penalty, support legal availability of abortion services for those who choose it, and oppose laws prohibiting drugs and prostitution. There is no contradiction there.