Even if people are content with their own lives, their "a collectively shared sense of doom and gloom about society" is a major influence on their "decisions about divisive societal issues, such as voting for extremist parties" and Trump, according to psychological research from the University of Groningen, the Netherlands, and elsewhere. From Scientific American:
Commentators have argued that people voted for Trump because of economic anxiety, negative attitudes toward immigration, religion and race, and "a class rebellion against educated elitists." While many of these insights may contribute to an explanation, they do not reveal the whole story. For instance, the popular belief that Trump's voters were mainly working class turns out to be inaccurate.
Instead, new psychological research suggests that it is not necessarily citizens' personal (dis)content with their lives that matters as much as the perceived Zeitgeist of our time: a powerful shared feeling that society is taking a turn for the worse…
Recent research has found a way to capture, at least in part, the "spirit of the time." We proposed that while Zeitgeist was originally a concept used by philosophers, it essentially describes a psychological experience. As such, in its broadest sense, the Zeitgeist can be defined as a collection of shared values, attitudes, norms, and ideas that exist within a society at a certain time. Measuring such a general phenomenon is difficult, but we found a way to capture the one aspect we were specifically interested in: our collectively shared awareness about the state of society, which currently is characterized by a sense of doom and gloom.
We reasoned that this sense of doom and gloom about society is rather tacit, applies to society as a whole instead of any one specific issue, and relates to something that intuitively "we all know to be true." Individuals have impressions about the extent to which people in general, are pessimistic or optimistic about the state of society. This implicit, generalized, collectively shared perception of how society is doing "colors" more specific ideas and judgments about society.