Ever notice how humans are the only species that are allowed to pass on their genetic fuckups to the next generation? Natural selection does a great job in the wild. The strong survive and the weak die out. Even with things that humans farm for food, be it plant or animal, humans go so far as to breed the most desirable genetic traits, but when it comes to our own species, we allow the weak, sick, stupid and psychotic to not only live, but breed as well.
The right to life and liberty sounds slightly retarded when you realize it also applies to those floundering on the bottom of the genepool, don't you think?