Anyhow, in the United States, all citizens have the vote, and an uneducated urban vote and an uneducated rural vote are both votes, though due to our unequal representation the rural vote is 'worth' more.
In the US, we scream bloody murder at most attempts to even out those starting point disparities that our ancestors caused... when I was in school, one favorite trick to do instead was to stick Magnet programs in poor schools to import kids from the rest of the city to try to bring up some of the numbers, rather than focusing on the kids who weren't doing well in the first place.
It makes for a wonderful self-fulfilling "these people are worth less because they accomplish less so it's out of our hands so we have no need to try to make right our past wrongs" story.
The logic being: better little-to-no government at all than one that does a terrible job.
Holding a degree is to a large extent a proxy for age. It used to be that not many people went to university. The concept that ~everyone (or at least 50%) should go to university is a relatively new one. So the numbers of people graduating over time has shot up. Hence if you select the population by whether they have a degree, you'll end up with a lot of young people. And youth is quite correlated with voting left.
The notion that holding a degree makes you inherently smarter than someone who doesn't is an increasingly suspicious one to many folks, like me. There are too many people with multiple PhDs writing academic papers that have major errors in them, signing off on papers that have major flaws, changing their supposedly expert opinions overnight for political reasons, saying things on Twitter that are totally bizarre and so on. Do universities really make you "educated" or do they just make you unwilling to question another "educated" person's opinions even when obviously wrong? My experience is that older people, people in more rural areas and those without a degree are more willing to engage in common-sense reasoning and reject nonsensical claims even when they come from an educated member of the elite, whereas degree holders find it far harder (perhaps because it would devalue their own degree).
You find derisive comments on rural areas throughout writings of the 19th and 20th century and it will probably still be reiterated for decades.
You're of course ignoring even worse problems on the Democrat side.
The lowest education rates and highest drop-out rates in the US are not in rural areas, they're almost exclusively in the inner cities where Democrats tend to completely dominate the vote.
Rural students at 87% are more likely to graduate from high school in four years than the national average at 83%.
The graduation rate by comparison in Washington DC public schools is typically around 65%-70%. Shall I list all the major blue cities by graduation rates, or is that not necessary because everyone already knows what the outcomes actually look like?
The persistent low education and high drop-out rate problems in so many major Democrat dominated cities (eg: Philly, Los Angeles, Baltimore, Detroit, Atlanta, Cleveland, Milwaukee, DC, etc.) is terrifying as an American. They're rates that low-development nations might be ashamed of.
The left pretends none of that exists when it's inconvenient, like when making blanket statements about Republican voter education levels.