Why did the attitude of americans change concerning the vietnam war?

The attitude of Americans concerning the Vietnam War changed as a result of the Tet Offensive.

The large number of US soldiers killed during the offensive, about 14,000, was not tolerated by the American people. The rejection of the war in the United States increased and that meant a turn of the war towards the defeat of the coalition. Some authors consider that it was a strategic victory due to the subsequent change that it caused in the US military strategy.

where is the section with the question?

congress was not thoroughly prohibiting states from funding religious schools.