Short answers, pulled from the story.
The Gulf of Tonkin Resolution gave President Lyndon B. Johnson legal power to use force in Southeast Asia without a formal declaration of war. Congress passed this joint resolution on the 5th of August 1964 following reported attacks by North Vietnamese torpedo boats.
President Lyndon B. Johnson worked closely with Defense Secretary Robert McNamara and Senate Foreign Relations Committee Chairman J. William Fulbright to secure passage of the resolution. Senator Wayne Morse led opposition efforts while Majority Leader Mike Mansfield facilitated the vote despite personal skepticism about the events.
The USS Maddox conducted patrols off the coast of North Vietnam on the 2nd of August 1964 and reported being attacked by three North Vietnamese Navy torpedo boats. A second alleged attack occurred early morning on the 4th of August 1964 which prompted Johnson to submit the resolution to Congress.
Johnson sought the resolution because it provided functional equivalent powers to declare war while avoiding the constitutional requirement for a formal congressional declaration. He also viewed the measure as an election year strategy to counter Republican opponent Barry Goldwater's campaign platform regarding Communism.
Congress passed the Joint Resolution to Repeal the Gulf of Tonkin Resolution on the 2nd of January 1970 after years of scrutiny and growing public opposition to the Vietnam War. Senator Wayne Morse had introduced motions to repeal the resolution starting in February 1966 arguing it was unconstitutional.