The United States had stepped in to support the continuation of Democracy in Vietnam. However, the people of Vietnam didn't like nor want the Diem family in power. The Diem family were supported by the U.S. due to their willingness to work with the US government and US businesses. The Vietnamese people saw corruption and abuse of power. Yet, despite legal elections, could not oust the Diem family.
"In 1958, the United States Supreme Court ruled that the state of Alabama violated the due process clause of the Fourteenth Amendment by requiring the National Association for the Advancement of Colored People (NAACP) to hand over the names and addresses of its members." ... States must protect the right to a lawyer.