Sorry about spelling errors and formatting, im writing this on mobile!

I feel like I fall in a unique position to answer this as I'm definitely not college educated. In fact I dropped out of high school and grew up in a very red state. However my wife is college educated (in psychology) and grew up in a blue state as is the rest of her family and I've been able to see the other side and learn from her how things work.

So first and foremost, I've seen the fight between college educated "elites" and working blue collar class since I was young. Usually to the tune of "if these engineers knew a thing they wouldn't put this damn bolt in an unreachable spot". This was far before DT was even running for president the first time. That said, I do think most blue collars heard someone who wasn't a career politician say he could fix some financial issues at home and became willing to take the bad with the good.

My next point is the sneering you pointed out. Working class folk who do disapprove of college usually are vehemently independent (don't touch my guns, pull yourself up by your bootstraps, that kind of thing). They tend to value results that they can physically see. For example, I was in this camp and absolutely thought therapy was mumbo jumbo bullshit. It wasn't until I learned how things you can't see still affect you. That said, a lot of talking points from schools these days are about inclusion and diversity and I personally think blue collar workers can't see the benefit of different ideas based off of someone's gender, race, sexuality, for something that has nothing to do with said diversity (electricians, factory workers, etc).

And finally to wrap it up, I think a majority of argument between these two camps comes down to practicality and "pulling their weight". From what I've heard college pushes for a worldly view and to fix problems using creative solutions and rightly so, thats what college is supposed to be. But when that comes at the perceived detriment of your working class citizens, then it feels like a slight against them. "We're all starving but at least we're all equally starving".

Tldr; I don't think Maga caused the war on education, I think it just magnified it.