Opposition to the war first emerged from the New Left and from black leaders such as Martin Luther King . By 1967 , there was growing opposition from within liberal ranks , led in 1968 by Senators Eugene McCarthy and Robert Kennedy . After Democratic President Lyndon Johnson announced in March 1968 that he would not run for re-election , Kennedy and McCarthy fought each other for the nomination , with Kennedy besting McCarthy in a series of Democratic primaries . The assassination of Kennedy removed him from the race and Vice President Hubert Humphrey emerged from the disastrous 1968 Democratic National Convention with the presidential nomination of a deeply divided party . Meanwhile , Alabama Governor George Wallace announced his third-party run and pulled in many working-class whites in the rural South and big-city North , most of whom had been staunch Democrats . Liberals led by the labor unions focused their attacks on Wallace while Nixon led a unified Republican Party to victory
assassination of Kennedy
Assassination of Robert F. Kennedy
Modern liberalism in the United States