Of course the question of consciousness is an heavily political issue, that doesn't make it a topic out of science.
First, generally speaking science is largely shaped through political decisions. Sure thought experiments and the kind of manual experiments that can be conducted by a solitary genius in its basement can lead to breakthrough, provided the said genius is indeed not limited by any external social pressure that prevent to freely dedicate its proper resources on its whims. But no single genius will make the Manhattan project or an LHC in its kitchen during its spare time.
Medicine is generally recognized as a science. Some areas of medicine do focus on the topic of consciousness. Medicine is also a sensitive political matter.
Especially the ability to experience suffering might offer reasonable basis for approaching ethical questions.
In terms of animal rights this is as simple as assuming that at least most vertebrae experience mental states, incl. suffering, from at least shortly after birth (which we can safely do)
In terms of abortion, this still leaves us with the additional question of weighing contrary interests of 2 individuals. This is trivial when weighing the interests of pregnant person vs sth like a 10-week fetus (obviously incapable of experiencing mental states) but maybe not sufficient for arguments about 30+ weeks fetuses, depending on personal values
Still, physiological responses are not the best indicator of mental states - plants and primitive animals (from sponges to bivalves) have them too, despite lacking the neurological development necessary for (or evolutionary need for) "consciousness".
And I agree that physiological responses aren't the best way to show mental states. I cry sometimes for no reason whatsoever, my eyes just leak; you can't infer fear just because a creature backs away from fire, either.