Here, OP, I wrote this before the jannies nuked the previous thread:
>the likely criminalization of abortion
I won't get into it here, but that's probably not gonna happen (at least not anytime soon).
>Is a fetus a human life that deserves rights?
There really isn't any satisfactory answer to the abortion debate. We have no metric for determining the relative sapience of a fetus, and even if we did, what exactly is the cut-off point for determining whether an abortion is morally justifiable? Should we stop if the fetus is capable of feeling pain? Even the most basic cell is reactive to painful stimuli, yet our bodies murder them by the trillions and we never give it a thought, and who's to say the fetus is capable of retaining any lasting memory or formulating an emotional response to being aborted? Consciousness is a gradient, not a binary, and there isn't any way to tell (for now) where an organism falls within that spectrum.
However, since we don't have any way to tell whether a fetus could hold any conscious objection to being terminated, I'd say that we should allow for the individual to decide for themselves. There's a possibility that we are hurting sapient human beings by allowing abortion to continue, but there's a definite possibility that you'll hurt many others by banning it.
>I think sentience ought to be the measure of whether something deserves rights.
"Deserves rights" is a slippery concept as well, though. Cows are sentient and are protected under animal abuse rights, but we willfully slaughter them by the billions for the sake of our own convenience and consumption.