Richard Nixon changed the way Americans looked at Presidents. He failed to stem stagflation despite wage and price controls and eventually was forced out of office under scandal. By 1974, the Vietnam War, Watergate, gas shortages and stagflation began to alter the way in which Americans thought of the Presidency and government.
The next two Presidents were outgunned in their ability to effectively deal with rising problems or at least provide an effective PR campaign otherwise. RR was the first President to really understand the importance of tapping into the American psyche. He claimed government was the problem but grew government. He railed against uncontrolled spending yet ran eye popping deficits and doubled the national debt. While he enjoyed an economic turnaround he presided over the beginning of the neoliberal state.
George Bush Sr. probably one of our more "moral" Presidents also proved ineffective to combat a quickly changing country or at least belt out optics that would suggest otherwise. He was no match for the slick and youthful Governor from Arkansas that had politics and wheeling and dealing running through his veins.
Clinton suffered what a lot of Presidents experience in their first years. They totally misunderstand the Washington dynamic and quickly find honoring promises is not easily done. After the 1994 mid terms Clinton got into his groove. He was never afraid of getting in the pit with the other vipers. He also understood the power of popular support. He played both like a fine tuned fiddle. The economic impact of the introduction of the Internet graced his second term.
Clinton like many of his predecessors couldn't keep it in his pants. Unfortunately for him he chose an impressionable young girl that couldn't keep a secret. Ultimately and unfairly this is what cost his VP to lose the 2000 election (the Supreme Court not withstanding).
Bush was nothing more than an empty suit being controlled by the neocons and Wall Street state, both of whom were let free under Clinton. 9/11 was the gift that gave big time to the neocons while sugar plum tales of the wonders of deregulation sent Wall Street into a risk leveraged orgy.
Obama promised a change to cure ineffective government and the end of the corporate state. But the young senator with no real political chops was no match for those on the other side. Moreover, the corporate state easily coopted the man posing as intellectuals and grand thinkers. The man was used.
This leads us to Trump. Nothing remotely like this in any memory. Some were faithful devotees. some saw him as the lesser of two evils and together that gave him an electoral college win. What Trump didn't realize is the number of insiders that planned for his demise. Far right wingers want him out so that Pence can move in and the far left want to neuter and render him totally useless. So far both sides have their plan progressing quite well. Time will tell if he can mount a successful resurgence.