“The element of hope has been taken away by the Tet Offensive,” noted Secretary of State Dean Rusk, “People don’t think there is likely to be an end.” Newsweek ran a cover story on February 19, with Westmoreland on the cover, entitled “Man on the Spot.”
By the time that Tet ended, Johnson was left with a massive credibility gap that overshadowed everything he had done on domestic policy. By March, when anti-war Democrat Senator Eugene McCarthy performed unexpectedly well in the New Hampshire primary, the polls had really turned on the president and the war. An initial spike in public support from Tet in February, with a notable increase in hawkish sentiment about Vietnam, turned hard against the administration in March. 49 percent of Americans thought the war was a mistake; only 41 percent thought it was the right decision. Only 35 percent believed that it would end within the next two years. His overall approval ratings for handling the war fell to a meager 26 percent. On the last day of the month, with his support plummeting, Johnson shocked the nation by going on television to announce that he would not run for reelection.
When rumors circulated that Westmoreland had asked for 206,000 more troops in response to Tet, Americans were outraged and the apparent blindness of the people in power. The Democratic Convention in 1968 was a disaster, as liberal Democrats and the anti-war movement opened up a civil war. Ironically, the person to reap the most benefits from the war was Richard Nixon, the next president of the United States, who lied and deceived the public about Vietnam in ways that even Johnson could not have imagined.
Besides the damage that Tet imposed on Johnson, the surprise attack and the revelation that the administration had vastly oversold the prospects for success were a severe blow to public confidence in American government leaders to tell the truth and to do the right thing.
The right also took its own lessons from Tet and other parts of the increasingly critical wartime coverage, namely that the media could not be trusted. As reporters focused on Tet as evidence of failure, hawkish Democrats and Republicans were quick to note, rightly so, that the U.S. counter-offensive had been successful. Johnson felt this way and tried to hammer away on the point that the media was misrepresenting what happened. For decades, coverage of Tet would remain to conservatives a symbol of why the “liberal establishment” could not be trusted to give the public a realistic assessment of national security issues.
For much of the nation, however, the specifics of Tet were beside the point. The real story was the context of the disastrous policies in Vietnam that cost thousands of American lives every month, undermined the nation’s moral authority in the Cold War, and didn’t seem to be working. As the historian Fred Logevall has argued, Tet is not the sole culprit behind the shattered faith from Vietnam, as opposition to the war and the realization of government falsehood had been growing for several years. But Tet still packed an extraordinarily powerful punch on a nation primed to be disillusioned. Based on what they were seeing in the winter of 1968, the communists in North Vietnam remained strong and determined, and promises that the war was ending were simply not true.