What John McCain may or may not have said to his wife was between the two of them. Such an exchange does not disparage all women anymore than some woman calling her husband a "dick" would be directed towards all men.
We cannot say the same about the what Michelle Obama may or may not have said, which, if said, would surprise no one. "Whitey" is an attempt to be insulting to a race of people. It cannot be exclusive to a second party. It does not compare to the John McCain situation.
Michelle Obama may have spent a lot of time inside rooms where information was imparted by a "teacher" under the guise of learning, but I would not describe her as being highly educated. If she is highly educated she hides it well. My take on Mrs. Obama is that what passes as her education is nothing more than uncritical mental absorption of misinformation, purposeful distortions, and socialistic indoctrination. She is actually a dumber woman now than she was before she was "educated".