In the Supreme Court case referenced above, it was 5% of their Federally allocated transportation costs. In this case, is 83% of Texas' Medicaid funding.
Later this month, the health insurance bill goes before the Supreme Court. It has a all or nothing federal monies tied to a state's setup of insurance exchanges. If the Supreme Court states that "no, that isn't coercive either", then fine, we've just given the Federal government unlimited power over the states. However, if it does state that its coersive, then we will at the very least understand what is coersive and what isn't, in respects to the Federal government and funding to the many states.
Its another case where states' rights are being challenged by the Federal government. I find it quite interesting.