"It's about dividing America," Brown said, adding that Sessions was acting more like Fox News than the country's top law enforcement official. "I call upon him to apologize to the people of California for bringing the mendacity of Washington to California and trying to insert discord and division, and I might add dysfunctionality, in a state that's really working."

Brown suggested that, given reports of President Donald Trump's unhappiness with the attorney general since he recused himself from an investigation into possible collusion between the Trump campaign and Russia, Sessions might simply be trying to keep his job.

In a statement, U.S. Department of Justice spokeswoman Sarah Isgur Flores said "the only war that has been declared by the Attorney General and the Trump Administration is on violent crime, transnational criminal organizations, and the drug crisis."

Senate Bill 54, Assembly Bill 103 and Assembly Bill 450 – the three laws that Sessions sued over – restrict California law enforcement officials from cooperating on federal immigration actions, limit the ability of local jails to contract with the federal government to house immigrant detainees, and require employers to ask for a warrant before allowing immigration authorities to conduct a workplace raid.

Commonly known as the "sanctuary state" law, SB 54 has been by far the most controversial. In its lawsuit, the federal government argued that it forces the release of immigrants who have already shown a willingness to engage in criminal activity.