Because the South Vietnamese leadership was in disarray, much of the burden of opposition fell on the US.
In February 1965, after a military base at Pleiku was attacked, Johnson ordered American bombings of the north in an attempt to destroy the depots and transportation lines responsible for the flow of North Vietnamese soldiers and supplies into the South. Four month later, President Johnson announced that American soldiers would now begin playing an active role in the conflict. By the end of 1965, more than 180,000 American combat troops were in Vietnam. IN 1966, that number doubled, and by the end of 1967, over 500,000American soldiers fought there. The war continued to intensified because several American strategies like “attrition, pacification, and hearts and minds” failed
horribly. There were specific political and social consequences about this war both in Vietnam and the U.S. In Vietnam, one strategy used by the US was called “hearts and minds”. They thought US soldiers could push Viet Cong from particular regions and then “pacify” those regions by winning their “hearts and minds.” routing the Viet Cong was often possible but the people still resisted and the army would have to be more heavy handed and basically destroy entire villages sending them to refugee camps or into the cities. By 1967, this war caused more than 3 million refugees which made the American military even more hated.
Stateside, the war dragged on for so long that political support for it began to erode. Students across the country were protesting the war by 1967 and enormous peace marches were held in New York, Washington and other cities. American opinion about the war was also influenced by the number of reporters and television cameras that were broadcasting directly from the war front.
Many politicians including Senator J. William Fulbright turned against the war and began to share his opinion publicly. After the Tet Offensive in 1968, opposition to the war grew substantially. Leading newspapers and magazines, television commentators, and mainstream politicians began taking public stands against the conflict. Public opposition to the war almost doubled and Johnson’s personal popularity rating had slid to 35 percent, the lowest of any president since Harry Truman.
Politically, Democrats begin to build support for a candidate to challenge Lyndon Johnson in the 1968 primaries because they wanted to elect a leader who would end the US involvement in Vietnam. Nixon did not win a decisive victory but the election made clear that a majority of the American electorate was interested in restoring stability.