Wrong. Supremacy clause. The Feds for example the FBI trump the state including sheriffs with respect to federal laws.
With respect to Federal Laws. And those laws are very defined and narrow in scope, unless of course, the feds scream Domestic Terrorism, which encompasses all things. Anything else and the Sheriff rules the roost. The Feds can’t enforce State law and if the SO isn’t part of the 287 Program, they don’t have to do anything.
So, Not wrong. The Sheriff of Mecklenburg County can tell the Feds to piss up a rope. Only time he can’t is when they Feds are investigating a federal crime within his jurisdiction. At that time the Sheriff, and deputies, can all get in their shiny Sheriff’s Office cars and drive away,not offer any assistance, nor do they have to accept any prisoners.
https://finance.townhall.com/columnists/maritanoon/2011/09/18/a-tree-party-rebellion-n1181453
http://sipseystreetirregulars.blogspot.com/2011/09/otero-county-tree-party-defies-feds.html
http://www.truthistreason.net/new-mexico-law-and-local-sheriff-trump-the-feds-in-agenda-21-land-grab ...............Otero County decided to put the State law into effect in order to thin out the forests to the test and notified the feds. The US Forest Service threatened to ARREST Congressman Steve Pearce and Otero County Commissioners! Otero County Sheriff Benny House reportedly advised the feds that if they made any arrests, he would then arrest the feds on kidnapping charges.
On September 17th, keeping his Oath of Office to the Constitution and the People, Sheriff Benny House and his SWAT Team protected the tree cutters. The feds backed down! The feds were absent from the Tree Party Rebellion. This is because within the county, the sheriff is the highest law enforcement authority in the land.