Here is the text:
> The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.
So take something like the ACA individual mandate. Does that violate the 10th amendment? Well, it was held to not be a valid exercise of the commerce clause power. But it was held to be a valid exercise of the taxing power. So it cannot violate the 10th amendment, because the taxing power is one of the ones "delegated to the United States by the Constitution." Say the Supreme Court had held it wasn't valid under the taxing power either. Would it violate the 10th amendment? Technically, but the Supreme Court wouldn't invoke the 10th amendment to strike it down, because a law not supported by one of the enumerated powers is invalid anyway.
The 10th amendment, by it's very language, cannot serve as any sort of independent check. If government action passes muster under one of the enumerated powers, it is by definition "delegated to the United States by the Constitution" and cannot violate the 10th amendment. If it doesn't, it's invalid by reason of not being within the government's enumerated powers--no 10th amendment necessary.
If you read the enumerated powers broadly enough, you are correct, but I find the 'generosity' of these interpretations to be quite disturbing. Commerce within the states is inter-state commerce, the Federal Government has a compelling governmental interest in your treatment of your neighbors, and whatever you produce or consume in your home affects the Federal Government's compelling interest in a regulatory scheme; everything not otherwise explicitly prohibited is fair game. Even the rights explicitly protected in the Constitution are subject to different levels of scrutiny, (i.e. rational, strict, etc. depending on how much the Judicial branch cares,) even when there was no provision for the Government ever violating them.