One characteristic of liberals is that they do not believe in IQ scores, except for their own exalted score, of course. (Does anyone except Joe Biden believe that Joe Biden's IQ is 146?) Liberals expect to make policy on the basis that the average IQ of all identifiable groups of people is not the same. They think that there should be as many black or Hispanic nuclear physicists as Asians, but that is just not going to happen in the real world. It takes an IQ of at least 106 to be successful in any major in college. Given that the average IQ of whites is one standard deviation (15 points)higher than black, and Asians average IQ is almost one and one-half standard deviations higher (21 or 22 points) there just aren't going to be as many black doctors and scientists percentagewise as Asiatics and whites. Politicians have a hard time dealing with this reality. Our country will suffer until they come to grips with this issue. Here is an informative discussion of this by Steve Sailer:

http://isteve.blogspot.com/2008/11/who-says-social-sciences-arent-sciences.html