[whammywon]

AFAIK most (all?) sheriffs can't be fired. They're elected county officials, so maybe they could be impeached but I really don't think they can be just outright fired like that.

Also, I would imagine many of the sheriffs that refuse to enforce mandates probably have considerable support from their constituents. Surely that would make their impeachment a significantly more difficult ordeal for whatever agency is responsible for the impeachment proceedings.