Picking the outspoken congressman for attorney general is Trump laying down a challenge, writes Anthony Zurcher.

The U.S. Justice Department and four states sued Tuesday to block UnitedHealth Group’s proposed $3.3 billion acquisition of Amedisys, a Louisiana-based home health company that would further United’s push into the home care and hospice markets.

Minnesota-based UnitedHealth Group Inc. is the focus of an antitrust lawsuit filed on Tuesday by the United States Department of Justice.

The Justice Department is suing to block UnitedHealth Group’s $3.3 billion purchase of Amedisys, citing concerns the combination would hinder access to home health and hospice services in the U.S.