Why did some Americans oppose the Vietnam War?

I think you are asking why some Americans are opposed to this war. I changed your question to reflect this

Many Americans who oppose war do this because they think that this is not a war essential for American security. They believe that what happened in Vietnam can not truly affect America. Other opponents of the war objected to them as they believed that the United States is trying to repress the Vietnamese. These leftists believe communism is better than capitalism. They feel the United States is a lively country, even though these ideas are not good for Vietnam, they try to promote their ideas.

Some people oppose the war based on morals and oppose the American capitalist who was modernized for farmers Vietnamese; as controversial, 2.5 million Americans from Vietnam 80% of military service comes from poverty background and working class. The 1968 US presidential election was the 46th fourth year presidential election held on Tuesday, November 5, 1968. Republican candidate, Former Richard Nixon Vice President won the election of Democratic candidate, and current vice president Hubert Humphrey. Nixon participated in a campaign to riot a city in the country and promise to restore the law and order to runaway

Richard Nixon pledges to the main campaign of Americans is that he ends the war with "Vietnamese" or systematic withdrawal. However, the United States still shows a high presence in Vietnam, the number of casualties is increasing, the costs of war are also increasing. Taxpayers will pay $ 25 billion a year for disputes that no one believes. (Columbia Encyclopedia, 6th Edition) Nixon's plan to attack Cambodia's communist supply site in 1970 failed and triggered another round of protest. In May 1970, the protests from Kent's students became fatal, at that time the National Guards fired into the crowd, killed four students and injured dozens. Students across the country were angry, and a couple of days later the campuses in the USA were stagnant. (Columbia Encyclopedia, 6th Edition)

During the Vietnam War, the majority of the US population objected to US involvement in Southeast Asia. Since 1967, public opinion has steadily opposed the war. It was only one third of Americans who believed that by 1970, the United States did not make a mistake by sending troops to fight in Vietnam. Nearly a third of the US population is strongly opposed to war. This situation has been going on for decades. Following the benefits of the 1954 Geneva Conference, the United States opposed participating in Vietnam. American support for Dirham's voting refusal is regarded as a defeat to democracy which the United States claims to support. Senator John F. Kennedy objected to participation in the Vietnam incident. Nevertheless, it is possible to designate specific groups and their causes to lead the antiwar movement during the peak hours of the late 1960s.