The 10a was originally intended to keep the Federal government from influencing anything not explicitly stated in the constitution. Granted the Federal government didn't actually follow this amendment, as they had already implemented the First Bank of the U.S.; and did not get rid of it when the 10a was passed. Ever since then, the Federal government has done whatever it wants, and no one has sued them all the way to the supreme court to get a ruling on it's constitutionality. Basically, the 10a only counts in philosophy, not in practice.
This is just my take on it; and I'm just an 18 yo kid who took a government class in High School.