I agree. Both Kennedy and Johnson were worried about getting re-elected. But Cronkite, “the most trusted man in America”, went on tv after the Tet Offensive, a major victory, and claimed it was a major defeat. That had a lot of influence. Vietnam is too complicated to blame any one person. But, if we had bombed the hell out of Hanoi early, and mined their harbors,it may have made a difference.