Not sure that's it in this case.
True, a lot of them can't tolerate a black guy in the White House, but I would guess the issue is more fundamental. He's not a Republican. So they attack. Bill Clinton was a moderate republican with a D after his name, so they attacked him incessantly. Obama is less moderate, but he's still got that D affiliation so bark, bark, bark... They can't help themselves. They are operating at a herd beast level. Once they get one of their own back in, everything will be OK again. They will still be competing with Holsteins at an intellectual level, but that's sorta normal.