There certainly are some blacks that have high levels of intelligence. These are usually the ones white people enounter in their suburban neighborhoods. But the plain truth is that most of them live in the inner city ghettos, and are in some respects much like monkies, with less control over their emotions, and not especially articulate. When progressives really begin to push for racial integration, and whites finally see what all those blacks (who now live separated away in the ghettos) are really like, there will become many more believers in racial differences.
Please, go to one of the black ghettos and take a look around. Do some observing. Develop friendships with blacks from these ghettos. Not to say that blacks are bad people- they tend to be especially jolly- but there are differences. The blacks you may have encountered in your insulated suburban white community or university are not representative of the black race. It would be like visiting an asian prison population and coming away thinking that asians were prone to crime. The blacks in the better neighborhoods are only there because they have the intelligence to afford to be there, and they have left their lower income regions to seek better opportunity outside.