To be sure I’m addressing your question properly and that we’re not talking past each other I’d need to know which specific people you’re thinking of, but just speaking generally off the top of my head, this is a sample of the kind of thing I meant:

• Generations of propaganda promoting countless forms of division and/or social hierarchy. This dilutes democratic efforts by pitting people against each other who should be on the same side. Not just the most well-known forms of bigotry but also the tendency of a lot of people to adopt the everyday elitist attitude that they’re smart while most other people aren’t, or that something obvious to them because of their own life experiences or education should be obvious to everyone else regardless of other people’s varied life experiences or education.
• A human tendency to conform to and defend the status quo at all costs (because our brains are always seeking stability), even when it runs counter to our own needs or values. This has been increasingly exploited by major political parties across the West to get people to vote based on vibes and personal affiliations rather than demanding trackable progress toward specific measurable outcomes. The UK is now shaping up to become an exception to this. Over there, urgency to end austerity has caught on as the outcome most people want, and now the debate is naturally shifting toward whether people believe the right way of doing so is to tax wealth more than work (Greens), or to kick out immigrants in the (in my opinion misguided) hope the wealthy will then decide they’ve taken enough and gladly share with whoever’s left (Reform).
• Unfortunately, power in and of itself begets “people who don’t like people.” There is a well-documented phenomenon for people with any level of power over others (could be wealth, elevated social position, a prestigious job, etc.) in which their capacity for empathy becomes impaired, which leads to all sorts of cascading effects that get reflected in both public and private institutions. (I’ve heard at least one researcher talk about ways to directly counter this with special coaching for people who get elected as public representatives, but it was a long while back so I’d have to do some digging to find that discussion again.) I think this covers leaders who think they’re doing the right thing but are woefully out of touch as well as the dangerously ambitious ones who might have convinced themselves otherwise at first but really only got into politics for clout and prestige.