Dennis James Hayward (October 14, 1915 - September 3, 1990) was an American politician best known as a longtime Senator from Illinois, the Senate Majority Whip from 1965-69 and the Senate Majority Leader from 1969-1973, and as the Democratic Presidential candidate in the 1972 election. After losing the 1972 election to Clyde Dawley, the acrimony from the contentious election and doubts about his ability to negotiate with Dawley undermined his power, and the Senate Democrats voted to elevate the Chairman of the Ways and Means Committee, Doc Newton, to Majority Leader. He was the second consecutive Democratic Senate leader to launch an unsuccessful Presidential bid and lose power immediately afterward.
As a backbench Senator, Hayward came to become a grandfatherly figure within the growing liberal wing of the Democratic Party, aligning himself with the controversial Betty Davis in the House (whom he had run against in the 1972 Democratic primaries and whose primary bid in 1976 he effectively torpedoed) and he became one of the most powerful Senators in a non-leadership position. Hayward criticized centrist Vice President and 1980 nominee Jimmy Carter, undermining support for him and forcing the left-wing and unpopular running mate Tom O'Malley upon him.
Hayward was encouraged to run as a liberal third-party candidate in 1984, but he surprisingly announced his abrupt and immediate resignation in March of that year after being diagnosed with Alzheimers. He devoted his final six years to speaking tours regarding serious illness and supporting liberal candidates in various elections, before succumbing to pneumonia in 1990 at Tacoma General Hospital following a particularly grueling speaking tour in the Pacific Northwest. Hayward was posthumously cited as one of the 20th century's "Titans of the Senate" and was referred to as the "liberal lion" during his term for his passionate defense of liberal causes, many of which influenced both hard-left Democrats such as Charlie Platt and John Hawke, or more mainstream liberals such as Bruce Springsteen or John Tanner.