From his official bio:

Often called  “one of the most courageous persons the Civil Rights Movement ever produced,” John Lewis has dedicated his life to protecting human rights, securing civil liberties, and building what he calls “The Beloved Community” in America.   His dedication to the highest ethical standards and moral principles has won him the admiration of many of his colleagues on both sides of the aisle in the United States Congress.

He has been called “the conscience of the U.S. Congress,” and Roll Call magazine has said, “John Lewis…is a genuine American hero and moral leader who commands widespread respect in the chamber.”