Joe Biden’s long history of friendships with segregationists in the U.S. Senate is suddenly emerging as a political issue after the presidential candidate this week fondly recalled working with two racists who were his fellow Democrats on Capitol Hill in the 1970s.

Through his nearly five decades in politics, Biden, 76, has praised or reminisced about working cordially with every major segregationist who served alongside him in the Senate, according to a Washington Examiner analysis based on a list of key segregation proponents compiled by the Equal Justice Initiative. In all, Biden has spoken warmly of or boasted about his ability to work with six men on the list.