Stupid people don't like smart people because smart people make them look and feel stupid, in comparison. So stupid people tend to stay stupid because they resent and avoid intelligence rather than admire it, and pursue it. Instead, they pretend that stupidity is some sort of folksy wisdom that smart people are too arrogant to appreciate. And that way they can feel better about themselves, and comfortable in their ignorance.
This is one aspect of the cultural divide in the U.S.
Another is about wealth distribution and it's relation to power. Capitalism gives the wealthy investor class control over the commercial enterprise that their capital is invested in, which the capitalists then use to capture yet more wealth. That is, after all, the sole purpose of capitalism. So as the wealthy become even more wealthy, they use some of that excess wealth to corrupt the government into representing their interests instead of the interests of the people the government is supposed to be representing. But to keep doing this, they also need to get a significant number of stupid people to vote for their corrupt politicians, in spite of the fact that those politicians will not serve those stupid people's best interests once in office. (Which is why these supporters need to be stupid.) So a system has been created to keep the stupid people among us stirred up, emotionally, and focusing their anger and resentment of smart people at the political opponents of the wealthy elites. Hence, the endless parade of "wedge issues" being pushed on the public by media outlets owned by the wealthy elites. And it works. The stupid people are sufficiently stirred up, and their resentments against smart people are sufficiently blinding, to get them to vote for corrupt politicians, and against their own best interests, in election after election. They are not the majority of citizens, but they are a sufficient enough number that along with gerrymandering and election-rigging, the corrupt politicians are able to get elected, and re-elected, time after time. And the wealthy elites continue to use them for their own economic gain.
So as the nation's wealth piles up in the hands of an increasingly powerful elite, the political corruption deepens, and the general population suffers the consequences. And the stupid people within that population suffer those consequences, the most. But unfortunately, instead of that suffering driving people together, and unifying them to enable them to take back their government and end it's corruption, it only drives stupid people to behave even more stupidly. So they "double down" on their anger and resentment of intelligence, and of intelligent people, and they vote for even the most obvious corrupt and criminally inclined political candidates, just to express their loathing for those "smart-a$$ed liberals" that they imagine hate them and loathe them as much as they hate and loathe the smart-a$$ed liberals.
So that as the rich continue to corrupt our government and use it to exploit the nation for all the wealth they can get, we end up turning more and more against each other, instead of turning against them, and unifying to take control of our government back , from them. And if this all goes on much longer, the corruption will have become so entrenched and disfiguring that we will no longer be able to overcome it using democratic means even if we do stop hating and blaming each other and decide to act together to take control of it back. And at that point, there will be no avoiding the bloody abyss into which we are heading.