President Trump has invoked a rarely used 1798 law that gives a president immense powers to arrest and deport noncitizens in a time of war, which he says exists in the form of a gang 'invasion.'

A federal judge said the Trump administration acted illegally when it deported a Maryland man in error to El Salvador, and ordered he be returned.

The government has deported hundreds of migrants over alleged gang ties, but their families claim their loved ones are innocent and lack due process.