Why is it that when Liberals want welfare the baby has rights but when they wanna kill it (its just a fetus)?

I am a conservative person, but I do agree with abortion. It is just not realistic to ban it in a world as screwed up as ours - our population would boom beyond belief, and think of all those stupid girls who get pregant at 14 years old and bring up a baby without any life experience or cash, therefore destroying 2 lifespans worth of work.