...can exist outside of the host's womb without HER specific care, then it is deserving of 'individual rights'.
Until that point, the fetus is nothing more than a parasite existing off of a willing and able host.
Why some would give or want to endow 'individual' status upon something that isn't is beyond me...
So what precisely is the practical difference between a second-trimester fetus and a social leech who refuses to contribute to the society which supports him? Both will die without the "host," as you so curiously put it.
But if I were king, I wouldn't make it illegal because then poor folks would find ways to terminate pregnancy while the middle class would have the means to travel to Boston or Canada.