WY
 

These fireworks could be interesting.

“I am reacting in response to the actions of federal employees who have attempted to deprive citizens of my county of their privacy, their liberty, and their property without regard to constitutional safeguards. I hope that more sheriffs all across America will join us in protecting their citizens from the illegal activities of the IRS, EPA, BATF, FBI, or any other federal agency that is operating outside the confines of constitutional law. Employees of the IRS and the EPA are no longer welcome in Bighorn County unless they intend to operate in conformance to constitutional law.”

Wyoming sheriffs put feds in their place « disinter

This kind of thing crops up now and again and inevitably gets struck down by a higher court. 10th amendment challenges very rarely gain any traction.