Gavin Newsom, California's recently inaugurated governor, announced on Monday that he would withdraw hundreds of the state's National Guard troops from the United States–Mexico border. Though Newsom's predecessor, Jerry Brown (another Democrat), had agreed to deploy the troops south after President Donald Trump formally asked multiple border state governors to send forces to the frontier, Newsom indicated that he believes the National Guard's deployment was more political than practical.
"The border 'emergency' is nothing more than a manufactured crisis—and CA's National Guard will not be part of this political theater," Newsom tweeted on Monday morning.
Newsom's clash with Trump comes less than a week after New Mexico's governor, Michelle Lujan Grisham, announced she would order her own state's National Guard troops back from the border. The discord between the governors and Trump reveals how controversial it has become for National Guard troops to operate on the border. Though every U.S. president since Ronald Reagan (including Trump's predecessor, Barack Obama) has requested some National Guard troops be sent to the border at one time or another, the resistance Trump has found among Democratic border state governors could mark a change in the way the National Guard operates on the frontier.
At the heart of the confrontation is the National Guard's unique role in the country's armed forces. Though the California National Guard troops on the border currently operate under federal instruction (and federal funding), Newsom maintains full authority over the Guard's deployment. This is because the Constitution and federal law guarantee that, in peacetime, the National Guard reports to the governor of its respective state: In other words, Newsom, not Trump, is the commander-in-chief of California's troops. This gives the new governor the power to materially resist Trump's agenda.
That said, Trump, as president, has the ability to federalize National Guard troops, with or without a governor's consent. But the deployment to the border Trump ordered last year used a different federal statute than the one that would nationalize the Guard: Instead, Trump formally requested that border state governors deploy National Guard troops (with the order to follow federal instruction).
Trump's request, made in the midst of the family separation crisis in April of 2018, met with immediate controversy. In California, Brown reportedly mulled over the request for a week, before sending the administration a letter in which he agreed to the deployment—but not without a series of serious caveats: "Let's be crystal clear on the scope of this mission," Brown wrote. "This will not be a mission to build a new wall. It will not be a mission to round up women and children or detain people escaping violence and seeking a better life. And the California National Guard will not be enforcing federal immigration laws."
At least some of Brown's caveats were unnecessary: the Posse Comitatus Act outlaws law enforcement by the U.S. military on U.S. soil, and prohibits members of the National Guard—along with federal troops—deployed on the border from making arrests. And though some troops did put up military-style razor wire on California's southern border, there is currently no plan for the army to build any wall.
In 2010, then-President Obama requested 1,200 National Guard troops to assist Border Patrol in the midst of staffing shortages in the Department of Homeland Security. Using military helicopters, Guard troops helped Border Patrol surveil the border and apprehend drug traffickers and smugglers. The deployment, called Operation Phalanx, lasted until 2017.
Obama's request for National Guard troops on the border met essentially no resistance: Democratic governors did not see the need to refuse a Democratic president, and Republican governors, in general, were in favor of greater security on the southern border. In fact, when Operation Phalanx ended, Texas Governor Greg Abbott and U.S. Senator John Cornyn (R-Texas) both attempted to pressure Obama to extend the program.
Besides the increase in political polarization—Newsom and Lujan Grisham were both elected in campaigns filled with anti-Trump messaging—the reason Trump's deployment has drawn such controversy might have to do with the president's own messaging. When Trump first requested the troops last year, he claimed: "Until we can have a wall and proper security, we are going to be guarding our border with our military. That's a big step, we really haven't done that before, or certainly not very much before." Though many of his predecessors had sent the military to the border, Trump's decision to frame the policy as something unprecedented might have helped make an otherwise routine request politically fraught.
Trump has also tried to back up his decision to send troops to the border with increasingly alarmist language regarding what he calls the country's "very dangerous southern border." The characterization drew criticism from Lujan Grisham: "New Mexico will not take part in the president's charade of border fear-mongering by misusing our diligent National Guard troops," the governor said in her February 5th announcement. Studies have found border towns across all border states to be among the safest in the country.