Los Angeles police have swiftly enforced a downtown curfew, making arrests moments after it took effect, deploying officers on horseback and using crowd control projectiles to break up a group of hundreds demonstrating against President Donald Trump’s immigration crackdown.

Gov. Greg Abbott, a staunch supporter of President Trump’s immigration agenda, is the first governor to call on the National Guard as protests spread to multiple cities.

White House "border czar" Tom Homan said that protests in Los Angeles are complicating immigration raids, making them more "difficult" and more "dangerous."

President Donald Trump’s deployment of military troops to California is forcing Democrats back onto politically perilous turf, as they look for ways to condemn Trump’s actions without being drawn into a broad debate over immigration or tying themselves to the chaotic scenes emerging from Los Angeles.

Hundreds of protesters marched through downtown Milwaukee to decry the Trump administration's immigration crackdown.

Abbott's comment—an acronym for "F–k Around Find Out"—came hours after hundreds of protestors began marching Monday night, from the Capitol to the J.J. Pickle Federal Building, chanting "no justice, no peace" and waving signs lambasting ICE. The demonstrations ended with police using tear gas to disperse those gathered.

Scenes of mayhem and violence have emerged from the protests in Los Angeles. Who are the people clashing with law enforcement and fueling the unrest?