Why did Vietnam cause massive protests and significant distrust in the government?

The Vietnam War was actually started under false pretenses--the U.S.S. Maddox was attacked off the coast of North Vietnam while electronically simulating an attack against radar defenses around Hanoi.  The United States reacted by mining Haiphong and bombing Hanoi.  In 1965, Lyndon Johnson escalated the war by sending in thousands more ground troops to fight alongside the South Vietnamese army.  The Vietnam War was not a traditional war because while there were set-piece battles, the...

The Vietnam War was actually started under false pretenses--the U.S.S. Maddox was attacked off the coast of North Vietnam while electronically simulating an attack against radar defenses around Hanoi.  The United States reacted by mining Haiphong and bombing Hanoi.  In 1965, Lyndon Johnson escalated the war by sending in thousands more ground troops to fight alongside the South Vietnamese army.  The Vietnam War was not a traditional war because while there were set-piece battles, the North Vietnamese Army worked closely with the Vietcong in order to create chaos behind the front lines.  Robert McNamara, Secretary of Defense under Kennedy and Johnson, claimed that America was winning the war in terms of tons of bombs dropped and enemy kill counts.  This was the message on the nightly televised news.  However, in 1968, North Vietnam launched the Tet Offensive against American military bases and the embassy in Saigon.  While the offensive was turned back and the North Vietnamese lost heavily, many Americans did not think that this was the action of an enemy in retreat; rather, the North Vietnamese Army looked strong despite what was being told on the nightly news.  Walter Cronkite actually went to Vietnam and during a report looked into the camera and asked Johnson what the truth really was about the war.  Due to pressure about the war, Johnson did not chose to run for president again in 1968.  

Another reason that the war was unpopular and created distrust was demographics--eighteen year olds could be drafted but one had to be 21 in order to vote--this would be changed in 1973 thanks to the Vietnam War.  Minorities served in larger numbers during the Vietnam War--this at a time when race issues were prominent in America.  Working-class and poor young men served as well, while upper-class young men often got draft deferments while going to college.  Corporations such as Boeing and Dupont received massive defense contracts to make helicopters and Agent Orange--some Americans questioned whether we needed to be in this war to protect South Vietnam from Communism or the stock prices of defense companies.  

Yet another reason for the distrust Americans felt was the improved coverage of the war. While in their living rooms, Americans saw the war unfold on television.  There are iconic photos of children running in terror when soldiers burned their villages.  Lieutenant Calley of My Lai infamy became a symbol of the callousness of that war.  Americans were not ready to experience that war was a very confusing, bloody thing, and some accused the government of war crimes when in reality American soldiers actually helped in South Vietnam more than they harmed.