The problem is the underlying belief that "stupid" people breed "stupid" children and "smart" people breed "smart" children. History does not generally hold this to be true. Read up on the 5 Good Roman Emperors :
http://en.wikipedia.org/wiki/Five_Good_Emperors#Five_Good_EmperorsThey specifically adopted poor/non-royal children and raised them to be the next emperor bypassing the 'breeding' lineage of the past. Eugenics as they saw it had directly led to Nero's rule.
Nature loves diversity and has made procreation for the human species a pleasurable experience to encourage it. Genius often arises from 'simple' genetic material. If you humans begin culling or weeding out culturally undesirable genetic strains you might be missing the bigger picture.
On a social level, having a voluntary taxation system, would mean people who abhor the welfare system wouldn't have their tax monies go to it...problem solved and done so without the tyranny of controlling others.
I find it interesting that those who advocate Eugenics are damn sure that their lineage would make it to the acceptable queue...I wonder why that is?

Or you could just say you hate blacks, spics, Jews, chinks, etc considering them inferior and through physical force would exterminate their future on this earth. Psychopathy is psychopathy regardless of the rhetoric it hinds behind...