Ammon Bundy, the leader of an anti-government militia, speaks to members of the media in front of the Malheur National Wildlife Refuge Headquarters on Jan. 6, 2016, near Burns, Ore. (Justin Sullivan/Getty Images)

Recently, the federal Bureau of Land Management fired a longtime employee, allegedly for blowing the whistle on the Trump administration’s refusal to enforce grazing policies on federal lands. The former employee, Craig Hoover, reported that agency managers have been instructing employees to stop enforcing grazing restrictions, thereby allowing ranchers and their cattle unfettered access to natural resources owned and managed by the federal government.

This enforcement decision follows years of political violence and threats against public employees who manage federal lands. The most widely known was a 400-person standoff led by rancher Cliven Bundy in 2014 and the 2016 armed occupation of the Malheur National Wildlife Refuge led by Bundy’s son Ammon. But these high-profile episodes are just the tip of the iceberg. BLM employees often face violence and threats for enforcing unpopular restrictions on the use of public lands out west.

The federal government owns more than 640 million acres of the country’s western lands. That volume means that the federal government relies on local county sheriffs to be their eyes and ears and backup. As a result, sheriffs’ attitudes make a big difference in how much violence BLM workers face, as my new research shows. Here’s how.

How I did my research

My research scrutinized the attitudes of local elected officials, especially sheriffs. Elected at the county level, sheriffs are law enforcement officials who, like other politicians, run campaigns based on their ideological views.

“Constitutionalist” sheriffs believe that the Constitution ordains sheriffs as the ultimate law enforcement authority, even above the federal government. These sheriffs use their elected office to thwart the enforcement of federal rules by challenging and undermining the authority of bureaucrats.

I wanted to know whether counties that elect constitutionalist sheriffs are more prone to civilian violence. To answer this question, I classified sheriffs as constitutionalists if they called themselves such in their campaigns or to the media, or if news articles described them acting or speaking against federal land ownership or federal authority on public lands.

I then analyzed all reports of violence in those counties toward the Bureau of Land Management between 1995 and 2015. The reports include the date and location of 500 physical assaults, verbal harassment and violent threats. I limited my study to the 414 counties in the 11 western areas where most BLM land is located.

Here’s what I found.

It matters which sheriff is in town.

Counties that elect constitutionalist sheriffs have higher rates of violence against employees of the federal Bureau of Land Management compared to other western counties that do not elect constitutionalist sheriffs.

Over the two decades studied, civilians attacked BLM employees in one-third of the counties. In counties with a constitutionalist sheriff, the rate of violence was over twice as high. Even after accounting for other factors such as partisanship and household income, counties that elect constitutionalist sheriffs are nearly 55 percent more likely to have episodes of political violence against federal employees.

Employee reports of violence identify clear political motivations for the harassment. For example, a female Forest Service ranger recounted an assault by a civilian, writing, “He started getting even more upset and said oh your just another one of those BLM sluts who think you can do whatever you want to make all our recreation go away.… He said your just one of those environmental b----es who just think that you know it all well you don’t know anything that everything is just fine you are just as stupid as the BLM.”

Constitutionalist sheriffs lower the costs of political violence

Think of violence and voting as opposite ways of influencing public policy. If citizens don’t believe they can influence policy decisions, sometimes they believe they can achieve their goals through unconventional political behavior, including violence. In fact, citizens who don’t want their rights to use federal lands limited by the government may reap quicker rewards by using violence to prevent the BLM from enforcing policy, compared the more traditional methods such as voting and contacting elected officials. For instance, endless accounts indicate that when faced with a violent threat from ranchers, BLM employees will often choose to allow illegal grazing rather than engage in armed conflict with citizens. By this logic, ranchers who are denied grazing permits should prefer using violence to access federal grazing lands, instead of enduring the slow and costly legislative process.

So how do we know that constitutionalist sheriffs play a role in driving up violence? After all, it could be that voters most opposed to the BLM are especially likely to elect such sheriffs. That may be. But I collected anecdotal evidence that illustrates ways in which constitutionalist sheriffs have facilitated violence against the federal government.

In 2003, Sheriff Lamont Smith of Kane County, Utah, destroyed over 30 “restricted access” signs posted on federal land, publicly undermining the authority of the federal government. Ten years later, Smith signed a pledge to block enforcement of President Barack Obama’s gun control executive action. That same year, while testifying in front of the Utah legislature, he called BLM’s presence “an assault on the sovereignty of the state of Utah.” Unsurprisingly, Kane County has the highest rate of violence against the BLM of Utah’s 29 counties.

Sheriffs are the eyes and ears of the federal government

A BLM law enforcement agent assigned to the Bundy standoff testified that the mission to round up Bundy’s cattle would have succeeded had “the local sheriff, whom Sagebrush Rebel-types tend to regard as the legitimate law of the land, might have been able to defuse the Bunkerville protest,” according to an interview by High Country News reporter Marshall Swearingen. Instead, constitutionalist sheriffs sided with the pro-Bundy protesters. The BLM was forced to admit defeat.

State and county politicians prefer to blame the federal government for unpopular policies that affect their constituents. Deflecting blame is an especially appealing tactic for handling land management issues for which there are few easy or affordable solutions. And although national news often overshadows local sheriff elections, these officials’ beliefs and behaviors affect federal employees’ safety — and can force those workers to change how they enforce controversial rules. When it becomes prohibitively dangerous for federal employees to enforce the law, ranchers like Cliven and Ammon Bundy benefit from free use of public lands.

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Zoe Nemerever (@ZoeNemerever) is a PhD candidate in political science at the University of California, San Diego.