The first political outcome of the war was that Lyndon Johnson did not try to run for president in 1968. More long lasting effects of the war include the fact that people trust the government much less than they used to. This comes in part from the feeling that the government did not tell the truth about the war.
Socially, I think the war helped to lead to our "culture wars" that we have today. The people who supported the war saw themselves as the real Americans whose values were under attack by the long-haired, anti-American protestors. This has helped lead to the conflict between traditional and non-traditional people today.
The political outcomes were quite significant emerging from Vietnam. The lesson that became apparent for President Johnson and those who followed was that the presentation for the case of war would forever be marked by clarity of vision, definite timetables, and perceptive understanding that can be easily relayed to the public. Since Vietnam, American presidents have been bound and tethered to these concepts in their desire to commit U.S. military forces abroad. Socially, the fabric of society also has been permanently changed since the Vietnam War. The spirit of questioning authority, not believing what is told from the White House, and the spirit of anti- war dissent has remained in the social tapestry since the Vietnam War. Politicians have had to reckon with both forces since the conflict that toppled down the Johnson Administration.