Final answer:
Protesters opposed the Vietnam War on moral grounds, objection to the draft, concern over resource diversion from domestic programs, and doubts about the legitimacy and purpose of the war.
Step-by-step explanation:
There were several reasons why protesters opposed the Vietnam War. One reason was moral objections, as many saw the conflict as a civil war into which the U.S. should not have intervened. A second reason related to the draft, with individuals objecting to being conscripted to fight in a war they did not support or see purpose in.
Thirdly, the war's detractors were concerned about the resources it diverted from domestic needs, such as anti-poverty programs, which civil rights leaders like Martin Luther King believed were being neglected. Finally, the difficulty in justifying the war, given the lack of a formal war declaration and the perception of the South Vietnamese government as illegitimate, made many Americans, particularly students, question the purpose of the U.S. involvement in Vietnam.