Davis was born in Parkdale, Arkansas, and educated at the University of Arkansas at Pine Bluff (B.A. in history, 1961), Chicago State University (M.S. in guidance, 1968) and the Union Institute & University in Cincinnati, Ohio (Ph.D. in public administration, 1977).
Davis worked as a government clerk, a high school teacher, executive director of the Greater Lawndale Conservation Commission, director of training at the Martin L. King Neighborhood Health Center, and executive director of the Westside Health Center before entering politics, where he represented Chicago's 29th Ward on the Chicago City Council from 1979 until 1990.
He challenged Congresswoman Cardiss Collins in Democratic primaries in 1984 and 1986, but lost both races. Davis was then elected to the Cook County Board of Commissioners, serving from 1990 to 1996 before entering the House. Davis had also waged an unsuccessful campaign against Chicago Mayor Richard M. Daley in the 1991 Democratic mayoral primary.
On December 6, 1995, Davis announced his candidacy for the 7th Congressional District, adding his name to the already announced Democratic candidates, including Alderman Percy Z. Giles, Cook County Board of Commissioners member Bobbie L. Steele, labor leader Ed Smith, and Alderman Dorothy Tillman. Five other Democratic candidates entered the race later: S. Mendenhall, Joan Sullivan, G. Winbush, Anthony Travis, and Joan Powell, making it the largest field of candidates for U.S. Congress in Illinois for 1996. Davis resided a block outside the 7th Congressional District, but he was familiar in the district..
Davis ran on the progressive Democratic platform popular in the district. He was pro-choice and supported gay rights, the ERA, single-payer health care, and some federal support for child nutrition and care.
In early January 1996, the FBI revealed its Operation Silver Shovel, which included an investigation into Alderman Percy Z. Giles. What Operation Silver Shovel may have done to undermine Giles's chances for election are unclear as he was already lagging with a mere 3% among likely Democratic primary voters in a mid-December poll compared to Davis’ 33%, Smith’s 8%, Tillman’s 7%, and Steele’s 6%. However, up until Operation Silver Shovel Giles did have Mayor Richard M. Daley's support and that of other well-known area figures—some of whom continued their support during the controversy.
On March 10, 1996, during a radio debate hosted by WMAQ-AM, Tillman and Smith called for Davis to reject the endorsement of former alderman candidate Wallace "Gator" Bradley, spokesman for convicted Gangster Disciples leader Larry Hoover. "Why do you keep badgering me with this question?" Davis replied. "You got a problem with something? You're not going to catch me going around saying I hate Gator Bradley… I'm not in the business of disavowing individuals. The good Lord said he hated sin, but not sinners. I'm not hating Gator Bradley. I disagree with those who commit crime and those who'd use drugs, but you won't catch me going around saying that I hate Gator Bradley." Davis never rejected Bradley’s endorsement during the campaign and after winning the primary claimed that Bradley’s endorsement played no role in the outcome, though Bradley asserted the contrary.
During the campaign, Tillman highlighted comments Davis made in an August 1970 issue of Ebony: “(T)he white female often gives the black man certain kinds of recognition that the black woman often does not give him." The Davis campaign countered that Davis was speaking as a psychologist in his role as a training director at a health center.
Although Davis was fully promoted as a Democratic candidate, he also ran as a New Party candidate. Supporting this was New Party’s celebration of him as the “first New Party member elected to the U.S. Congress.” Although the State of Illinois did not permit fusion voting, New Party advocated fusion voting as a means to promote their party and party agenda and to particularly project New Party ideology into the mainstream Democratic Party. Candidates were referred to as “N[ew]P[arty] Democrats” and were required to sign a contract mandating a “visible and active relationship” with New Party. During this timeframe, New Party was experiencing substantial growth. Davis also received the endorsement of the Chicago Democratic Socialists of America (CDSA) of which he is a member and had a relationship pre-dating his congressional run. ACORN, AFL-CIO, Sierra Club, and International Brotherhood of Teamsters are included in other groups also endorsing Davis in his bid.
In the March 20 Democratic primaries, Davis received more votes than the two closest candidates — Tillman and Smith — combined. The first five announced candidates all received more than double the five late-entering candidates with none of the latter receiving more than 2,700 votes.
In the November 5 general election, Davis won with over 82 percent of the votes cast over Republican Randy Borow and third-party candidates Chauncey L. Stroud (Independent), Toietta Dixon (Libertarian), and Charles A. Winter (Natural Law).United States House Committee on Ways and Means
Chair of the Congressional Postal Caucus
Davis expressed interest in being President Barack Obama's replacement in the U.S. Senate, and Illinois Governor in late 2008 before Blagojevich's major scandal erupted. In a December 31, 2008, article published on the website of The New York Times, Davis said that he turned down an offer from representatives of Blagojevich to appoint him to the Senate. Instead, Blagojevich appointed Roland Burris.
In 2004, Davis was met with national controversy when he crowned the late Rev. Sun Myung Moon in a religious ceremony at the Dirksen Senate Office Building honoring the controversial spiritual leader. Moon declared himself the Messiah at the crowning ceremony, in which Davis appeared on the invitation as a sponsoring co-chair. Davis wore white gloves and carried the crown on a pillow to crown Moon and his wife "the King and Queen of Peace." Davis told Christian Challenge that Moon declaring himself the Messiah "was similar to a baseball team owner telling team members that 'we are the greatest team on earth'" prior to a baseball game. Davis said the peace awards were to "recognize people for promoting peace. Of course the highest recognition goes to the highest promoter and the highest promoter is Reverend Moon, so they come up with something higher than the certificates and plaques that other folks get." Other lawmakers who attended included Senator Mark Dayton (D-Minn.), Representatives Roscoe Bartlett (R-Md.) and Elijah Cummings (D-Md.), as well as former Representative Walter Fauntroy (D-D.C.) . Key organizers of the event included George Augustus Stallings, Jr., a controversial former Roman Catholic priest who had been married by Moon, and Michael Jenkins, the president of the Unification Church of the United States at that time. Salon later said that Davis was the only member of Congress in attendance who took pride in the ceremony, and that he has accepted money from fundraisers organized by Moon. In 2003, Davis gave a speech on the House floor and praised Moon, along with Congressman Curt Weldon. Davis said, "Many of my colleagues will join me and the gentleman from Pennsylvania Mr. Weldon, co-chair, in giving tribute to some of the outstanding Americans from our districts. We are grateful to the founders of Ambassadors for Peace, the Reverend and Mrs. Sun Myung [Moon], for promoting the vision of world peace, and we commend them for their work."
As the 15th most prolific traveler in Congress, Davis stirred up controversy by accepting a trip to Sri Lanka in 2005 on behalf of the Tamil minority there, paid for by the Tamil Tigers, a group that the U.S. government has designated as a terrorist organization for its use of suicide bombers and child soldiers. Davis said that he was unaware that the Tigers were the source of the trip's funding.
In February of 2012 Davis received the Chris Hani/ Rudy Lozano social justice award from People's World, a division of the Communist Party U.S.A. (See video under external links) Chris Hani was head of the South African Communist Party in the 90's.
Davis is married to Vera G. Davis. They have two children, Jonathan and Stacey Davis is a member of Alpha Phi Alpha fraternity. Davis is notable for his support of the National Federation of the Blind. He spoke at their conventions in 2004 and 2005.
On November 18, 2016, Davis' 15-year-old grandson, Javon Wilson, was murdered during a home invasion robbery in Chicago's Englewood neighborhood.