The Presidents didn't change.
What changed was that (in a very smally way) Americans realized that their government was capable of producing propaganda. They still don't fully understand the full extent of governmental (and corporate!) propaganda efforts. Most, I'd say, will maintain today that the Soviet government produced and Russian government produces vastly more propaganda than does ours. Which is, or course, horseshit. We are second to none in the production of vastly more effective propaganda both in the public and private sector - with the private sector just nudging out our government. Viet Nam, for the first time peeled back the tiniest edge of the mask our Presidents, government officials and corporate masters have always been presenting to us.
