I think liberals start out basically unhappy, then seek out a belief system that reinforces and justifies that unhappiness. This way they can wallow in their unhappiness and feel no obligation to change it, because
it's not their fault. Rather, it's the fault of the corporations, or the system, or the patriarchal church, or the vast right-wing conspiracy, or etc., etc.
It's no surprise that there is a correlation between drug use and liberal political beliefs, because in many respects liberalism is a drug of choice. See, by embracing liberalism, you abdicate all responsibility for your own life, and your unhappiness and boredom becomes a problem that someone else is required to fix in order to make you stop whining.