Military-style vehicles and National Guards troops have blocked a portion of 4th Street in front of the Ronald Reagan Federal Building and Courthouse.

The people of Los Angeles and surrounding areas have taken a courageous stand against Trump’s reign of terror targeting immigrant families,” according to organizers in a social media post about the planned protest.

Monday's protests were largely calmer than Sunday's clashes. California officials insist that the 4,000 National Guards troops and 700 active duty Marines en route to L.A. are an unnecessary abuse of power by Trump.

According to experts, Trump is the first President to deploy the National Guard without a request from the state Governor since 1965, when President Lyndon B. Johnson sent federal troops to Alabama to protect those partaking in a civil rights march from Selma to Montgomery, led by Martin Luther King Jr.

President Donald Trump deployed the National Guard to respond to anti-immigration raid protests in the Los Angeles area, with Gov. Gavin Newsom arguing that Trump is trying to "manufacture a crisis." The Morning Joe panel discusses.

HOW WE GOT HERE: The protests erupted after Immigration Customs Enforcement (ICE) officers on Friday carried out raids in three locations across L.A., where dozens of people were taken into custody. Newsom called the raids “chaotic federal sweeps” that aimed to fill an “arbitrary arrest quota.”

The California Governor has sued the U.S. President over the mobilization of the National Guard, calling it “an unmistakable step toward authoritarianism.”

Residents and experts say the response is reminiscent of a longstanding dynamic in the state and around the country.