Matthews, who recently battled prostate cancer, has for the last 25 years been the outspoken host of Hardball, which began in 1994 on NBC’s now-defunct America’s Talking channel. He began his career as a political aide on Capitol Hill for several Democratic congressmen, including a six-year stint as chief of staff to longtime Speaker of the House Thomas P. O’Neill. Matthews also worked as the Washington bureau chief for the San Francisco Examiner and as a columnist for the San Francisco Chronicle.