The election of JFK was the initial triumph of incandescent boolshiite over even the semblance of productive electoral thought processes. Even then, it took massive vote fraud in Texas and Illinois to put the SOB in.
Vietnam? JFK was specifically warned by President Eisenhower AND General MacArthur to not commit American troops beyond the rather low-key, non-uniformed advisory, supply, and training roles in which we were engaged. Vietnam? It was JFK's show. However, to this day, the post 1960's people blame the war on Nixon ... who ended it; disastrously to be sure.
The disaster in Vietnam happened on LBJ’s watch.