Since 1984, Clarence has been a columnist and member of the editorial staff of the Chicago Tribune, and his column is syndicated nationally by Tribune Media Services. Clarence serves The NewsHour as an essayist and as a frequent member of the program's panel of regional newspaper editors and columnists. He is also an occasional guest panelist on The MacLaughlin Group. Clarence's previous activities include 11 years as a reporter and assistant city editor for the Chicago Tribune; serving as community affairs director, reporter and planning editor at WBBM-TV; and writing for Chicago Magazine, The Chicago Reader, Washington Monthly, The New Republic, The Wall Street Journal, New York Newsday, and Emerge.

Clarence won a 1989 Pulitzer Prize for commentary, as well as a 1980 Illinois UPI Award for community service, the Edward Scott Beck Award for overseas reporting, and the 1987 American Civil Liberties Union James P. McGuire Award for his columns on constitutional rights. In addition, Clarence participated in a 1972 Chicago Tribune Task Force series on voter fraud, which also won a Pulitzer.

Clarence is married, has one child, and lives in Washington, D.C.