California’s ongoing battle against President Donald Trump’s deployment of military troops to Los Angeles is rooted in a 19th-century statute with a grim historical background — the Posse Comitatus Act of 1878. This law prohibits military personnel from enforcing civilian laws, a key point raised in a recent ruling by Senior U.S. District Judge Charles R. Breyer, who mandated that the federal government provide evidence to state officials to support their claim that the military’s actions in Southern California breach this important statute.
Judge Breyer’s order signals a significant turning point in California’s legal efforts, permitting “limited expedited discovery” to scrutinize how President Trump has utilized the federalized National Guard and Marines since their deployment in early June.
“How President Trump has used and is using the federalized National Guard and the Marines since deploying them at the beginning of June is plainly relevant to the Posse Comitatus Act,” Breyer wrote in his decision.
The Trump administration has already raised objections to the discovery and previously succeeded in overturning a broader ruling from Judge Breyer that would have restricted the White House’s authority over the troops, a decision later reversed by the 9th Circuit Court of Appeals.
In this latest ruling, the Northern District of California judge maintained a narrow focus, emphasizing that discovery would only pertain to the Posse Comitatus Act — a crucial development in the state’s efforts to limit military involvement in immigration enforcement.
The Posse Comitatus Act, which emerged in the chaotic aftermath of the Civil War, was introduced to address the violent resistance the federal government encountered while attempting to rebuild Southern state governments and enforce federal laws post-slavery.
While the law itself is concise, consisting of just over 60 words, its implications have been profound, marking both the end of Reconstruction and the beginning of Jim Crow.
Mark P. Nevitt, a law professor at Emory University and an authority on the statute, notes its unsettling origins.
Historically, prior to the Civil War, the U.S. military was relatively small, largely as a response to the oppressive practices colonists faced under British rule.
Local authorities could organize civilian groups, known as posses comitatus, to assist in maintaining order, a practice that occasionally occurred during events such as the California Gold Rush.
Utilization of federal troops for law enforcement remained rare and widely unpopular, with significant past events, like the enforcement of the Fugitive Slave Act, having instigated considerable backlash, ultimately contributing to the onset of the Civil War.
Recently, the Trump administration has drawn on constitutional principles akin to those used to enforce the Fugitive Slave Act as they justify deploying troops for immigration enforcement.
Josh Dubbert, a historian at the Rutherford B. Hayes Presidential Library, emphasizes the historical parallels, observing that Southern leaders avidly supported posse comitatus during the era of the Fugitive Slave Act.
By 1867, when federal troops began to engage in earnest Reconstruction efforts, conditions had drastically changed.
Calhoun Jacob, a professor of American history at Wabash College, highlights the immense violence of that period, noting how white mob violence, such as the destruction of Black neighborhoods in Memphis and the massacre of Black demonstrators in New Orleans, led to a military presence throughout much of the South.
Most Americans are unaware of the extent of racial violence that characterized the Reconstruction era, according to Calhoun.
Consequently, many citizens were subjected to intimidation at the polls, with white gangs resorting to violence to obstruct Black voter participation.
The threat of military interference in elections has been viewed as particularly alarming in American history.
The language of the Posse Comitatus Act was introduced into an appropriations bill by Southern Democrats following their electoral victory in the 1876 election, regarded as one of history’s most violent contests.
Post-war white lawmakers sought to fortify their grip on control over the South while simultaneously preventing federal troops from supporting local militias that protected Black citizens.
According to Dubbert, white Southern lawmakers were intent on restricting military presence once they regained power in Congress.
This effort was bolstered by some Republicans, particularly those opposed to the employment of federal troops during the 1877 Railroad Strike, which was the first national labor strike in the United States.
Calhoun characterizes this moment as a politically charged surrender of the South back to ex-Confederates, further entrenching systemic racial violence.
However, for most of the next century, the Posse Comitatus Act faded into obscurity, remaining largely unutilized until the mid-20th century when issues surrounding military intervention began resurfacing.
Nevitt elucidates that the law entered legal discourse primarily post-World War II with significant cases arising around military conduct concerning searches, arrests, and detentions of civilians — activities typically associated with civil law enforcement bodies like the LAPD.
On numerous occasions, courts upheld the principle that military and defense personnel should refrain from intervening in civil law enforcement unless faced with extreme circumstances, such as rebellion.
“Our nation was forged in large part because the British military was violating the civil rights of colonists in New England,” Nevitt reflects.
Given the broader implications of the law, scholars note several loopholes, especially regarding the National Guard.
The Justice Department contends that the Posse Comitatus Act does not pertain to the current military operations in Southern California, stating that even if it did, no violations have occurred by the soldiers stationed there.
Furthermore, the government argues that the 9th Circuit’s prior endorsement of Trump’s authority to summon troops rendered the Posse Comitatus Act issue irrelevant.
However, several legal experts assert that California’s legal position is strong.
Shilpi Agarwal, legal director of the ACLU of Northern California, remarked, “You literally have military roaming the streets of Los Angeles with civilian law enforcement. That’s exactly what the [act] is designed to prevent.”
Nevitt expresses skepticism about California’s chances, suggesting that even if Judge Breyer rules against the Trump administration, that decision would likely be overturned by the 9th Circuit.
He emphasizes, “It’s going to be an uphill battle. And if they find a way to get to the Supreme Court, I see the Supreme Court siding with Trump as well.”
image source from：latimes
