Question: What is the name of this American politician, member of the Minnesta Democratic-Farmer-Labor Party, the U.S. Representative for Minnesota's 7 congressional district, and the most senior representative from Minnesota, representing Dewey Township, Roseau County, Minnesota?  
Sentence (from "Dewey Township, Roseau County, Minnesota"): Dewey is in the 7th congressional district of Minnesota and is represented by Democrat Collin Peterson.
Relevant evidence: Yes