This is not hard:
1. He claimed three or four of the most highly educated successful black women didn't have the brain processing power to be taken seriously.
2. He didn't say they didn't work hard to get where they were (a common complaint about affirmative action). He said they lacked the "brain processing power to be taken seriously." That's like saying a good college quarterback is serviceable, but he's never going to have the athletic talent necessary for stardom in the NFL. Most people think of brain processing power/athletic ability as being something you were born with or simply lack.
3. If he said that about these three or four highly educated, successful black women, do you honestly (and in good faith) believe he thought less educated and less successful black women had just as much "brain processing power" as other racial groups and more "brain processing power" than these three or four black women? Because if you're going to go with the "Charlie's not racist" argument, that proposition is what you have to accept.