I can see how some might view it as racist if someone criticizes Obama for spending too much if that same person did not criticize Bush for the same practice. (Libertarians have been critical of both Bushes and Obama.) But there are other plausible explanations for the inconsistency:
1. They were not aware of Bush's spending practices.
2. They have become more fiscally conservative.
3. Bush's spending was beneath their threshold but Obama has exceeded it
4. They are party hacks.