December 9, 1912 – January 5, 1994

 O’Neill was elected to the United States House of Representatives in 1952. The seat was being vacated by Senator-elect John F. Kennedy (who had just been elected to serve his first term). During his second term in the House, he was selected to the House Rules Committee where he proved a crucial soldier for the Democratic leadership, particularly Speaker John W. McCormack.

In 1967, O’Neill openly criticized President Lyndon B. Johnson and the Vietnam War. In a meeting at the White House, O’Neill told the President: “In my heart and in my conscience I believe your policy is wrong.” During the Vietnam era, many notable politicians that were opposed to the war were voted out of office because some viewed their stances as anti-American and labeled them as being soft on national defense.

While O’Neill lost the support of some components of his political base, he benefited from the support of the many students and faculty on the many colleges and universities within his district. Within the House itself, O’Neill became more popular in part due to his stance on the war, particularly after leading an effort to reform unrecorded “teller” voting on amendments in the House. O’Neill won the trust and support of younger House members who also had the same stance on Vietnam, and they became important friends as O’Neill rose in power throughout the House.

In 1971, O’Neill was appointed Majority Whip in the House, the number three position for the Democratic Party in the House. In 1973, he was elected House Majority Leader, after Hale Boggs died in an plane crash in Alaska. As the majority leader, O’Neill was the most prominent Democrat in the House to call in 1973 for an investigation and possible impeachment of President Richard Nixon because of the Watergate scandal.

O’Neill became a leading opponent of the Reagan administration’s domestic and defense policies. This political rivalry was comparable to that of Speaker Newt Gingrich and President Bill Clinton in the 1990s. O’Neill called Reagan the most ignorant man who had ever occupied the White House. O’Neill also said that Reagan was “Herbert Hoover with a smile” and “a cheerleader for selfishness”. He also said that Reagan’s policies meant that his presidency meant it was “One big Christmas party for the rich”. Privately, O’Neill and Reagan were always on cordial terms, or as Reagan himself put it in his memoirs, they were only friends “after 5PM”.