The U.S. government's unprecedented use of National Guard troops in Los Angeles to protect officers carrying out President Donald Trump's immigration crackdown was illegal and should be ended, a lawyer for the state of California told a federal judge on Tuesday.

Lawyers for President Trump and Gov. Gavin Newsom faced off over the National Guard deployment in Los Angeles — and debated whether they were subject to a "constitutional exception.

Lawyers for President Donald Trump and California Gov. Gavin Newsom are set to face off Monday to determine whether the president violated a 147-year-old law when he deployed the National Guard to quell anti-immigration enforcement protests in Los Angeles – against the wishes of the governor.