For 50+ years most Americans, both conservative and liberal have felt they and their country are headed in the wrong direction, this despite a decent standard of living, a reasonably clean environment, and above average life expectancy. Europeans, on the other hand are happier and more content than Americans, this despite a standard of living that is no better than in the USA.
Some interesting reading in the link below:
Why Are Europeans So Much Happier Than Americans?
In all seriousness, the country is extremely partisan for a major democracy. Republicans never accept dems in office which creates the hatred and consequently unhappiness. It's self inflicted. .
Everyday it is demonstrated on here that a compete lack of understanding and continual believe of lies etc, indicates a poor education.
The partisanship is exacerbating by racism along party lines. Dems are associated with blacks, so repigs say.
The fraudulent election garbage has driven a societal wedge which will take generations to dissolve. There again, lack of education. Conspiracy theories.
You name it. They hate it