If I may butt in - forbidden how? I'm not aware of any constitutional prohibition.
A government can tax its own functions but not those of another government. Madison made the base principal behind the authority of federal government under the Constitution very clear.
James Madison, Federalist #39:
Contrary to popular terminology we have a "NATIONAL" government under the Constitution not "FEDERAL". Just as we are a REPUBLIC and not a confederacy nor a "DEMOCRACY.
As far as Quotes and such being collectable by state, the may be asked to do so, but not compelled. The ultimate power the National government wields is the power to require compliance of the individual within the state, which is why all examples of the imposition of direct taxes included provision for the Federal government to demand payment of assessed federal tax immediately from the land owner should the state choose not to act as collection agent in gathering those taxes:
James Madison, Federalist #45:
The Courts enforce the Constitution limits of taxation in just that light.
We are not operating under the Articles of Confederation that some folks seem to want us to be, we are operating under the Constitution of the United States. The Articles failed and the nation almost dissolved over the inability of a "FEDERAL" government to enforce the collection of taxes from states short of going to war with them. That is one of the basic reasons why we now have the Constitution.