McCarthy's opposition to the Vietnam War began in the early 1960s, when he expressed concern about the escalating conflict. In 1964, he voted against the Gulf of Tonkin Resolution, which authorized the use of military force in Vietnam. In the years that followed, McCarthy became increasingly vocal in his criticism of the war, arguing that it was unwinnable and that it was causing unnecessary suffering for the Vietnamese people.
In 1968, McCarthy decided to challenge Johnson in the Democratic presidential primaries. His campaign was based on his opposition to the war and his promise to end it quickly and honorably. McCarthy's campaign gained momentum in the early months of 1968, and he won several primaries, including the New Hampshire primary.
Johnson's decision to escalate the war in Vietnam in March 1968 further boosted McCarthy's campaign. The war was becoming increasingly unpopular with the American public, and McCarthy's message of peace and withdrawal resonated with many voters. In the end, McCarthy lost the nomination to Johnson, but his strong showing in the primaries helped to persuade Johnson to withdraw from the race and announce that he would not seek re-election.
McCarthy's opposition to the Vietnam War was a significant factor in the eventual end of the conflict. His willingness to challenge the status quo and his passionate advocacy for peace helped to turn the tide of public opinion against the war. McCarthy's legacy as an anti-war activist continues to inspire those who work for peace and justice around the world.