The Trump administration, which flooded Minnesota with immigration agents this year, argued that policies limiting cooperation with ICE were unconstitutional.
One establishment candidate dropped out and another rejoined the race amid worries from some moderate Democrats that a democratic socialist might win the primary.
Mary Moriarty, the chief prosecutor in Hennepin County, speaking at a news conference at the Hennepin County Government Center in Minneapolis on Monday.
A federal magistrate judge said Andrew S. Boutros, the U.S. attorney in Chicago, violated an order sealing a criminal case when he spoke at a news conference.
The former Wisconsin judge, Hannah C. Dugan, was accused of ushering an undocumented immigrant out a side door as federal agents waited for him near her Milwaukee courtroom.