http://en.m.wikipedia.org/wiki/Federal_government_of_the_Uni...Did you want published evidence of the structure of the government, or my personal conclusions?
If you don't believe the federal government is far and away more powerful and influential than all lower governments, just follow the money:
http://www.irs.gov/taxstats/
Tons of info there on US tax revenue.
If you are more specific with what you want me to cite, I could provide better citation.