If President Trump deploys troops to other American cities, experts say it would be a clear departure from founding principles and invite a legal challenge.

After court battles led to unfavorable rulings on ICE raids and other issues, the White House appears ready to keep pushing the limits of judges' tolerance.

A federal judge is hearing arguments on whether military troops deployed this summer by the Trump administration to Los Angeles violated a federal law that bars troops from conducting law enforcement duties within the country.