Opposition is not racist in itself.
No doubt, most of the opposition to candidates such as Condi Rice or Justice Thomas and so on is based upon principle (albeit bad principle) but the way that opposition is voiced is quite nasty and yes racist.
When talking about how President Bush's committment to getting minorities into senior levels of government come up, the left usually claims one of two broad cases.
Tokenism. The famous line is "inclusion illusion". This is easily refutable by looking at the composition of recent cabinets. Quite frankly Jesse Jackson can talk all he wants but in the end action counts not talk.
Uncle Tom. The other tack the left usually takes is to dismiss the nominated minority as some sort of stupid fool who is betraying the cause of minorities. This is particularly egregious because it persecutes those who do not agree with the group.
No, opposition to Dr. Rice is not based on race but the left is void of arguments to defeat her so the hate comes pouring out. Do not even get me started on what would happen if the roles were reversed.