An increasing number of U.S. sheriffs claim that they will not enforce gun safety policies from state and federal governments in their counties. As locally elected law enforcement with a unique institutional position and significant powers, sheriffs play a key role in local policy implementation. To better understand cooperation (or the lack thereof) between levels of government, we look at these sheriffs’ contentious relationships over firearm regulation. We argue that sheriffs mobilized to resist state and federal gun safety policies through right-wing extremist efforts, tracing the involvement of sheriffs in gun policy over time. Using two surveys of sheriffs (conducted in 2012 and 2021), we show that sheriffs’ preferences against gun safety measures relate to right-wing extremist attitudes, even with controls for political and demographic factors. We demonstrate relationships between sheriffs’ right-wing extremism and an expressed reluctance to support or enforce a wide set of gun safety policies.