academic left doesn't exist

The surveys in this Wikipedia article claim otherwise.

Some of those studies are suspect (e.g. most target social sciences, instead of a survey over all disciplines), but there does seem to be evidence that academics tend to lean left. For teachers at K-12 schools, this article cites a study about political bias, which found a smaller but still left leaning gap in political affiliation of teachers.

But the real question is whether that matters.

I grew up in a progressive state with largely progressive teachers and conservative parents. I considered myself conservative for many years (well into college, which was a private, conservative university), until several years after finishing school and I realized I really just wanted smaller, accountable government. Neither major party actually pushed for that, though both pushed for some aspect of what I wanted (Dems pushed for social policies like same sex marriage and legal marijuana, Reps pushed for lower taxes and spending caps).

Did my teachers influence my political views? Absolutely! But they didn't turn me into a progressive, they just gave me an alternative perspective from what I got at home. My most influential teacher was in 4th grade, who pushed hard for recycling and reuse (we has a class compost bin, mild consequences for improper waste disposal, etc). I'm no tree hugger, but I'm really careful about reducing waste. My parents cared about waste a lot too, but my teacher gave the perspective I needed to understand why it was so important (we had a guest speaker talk about aquifers, ground water poisoning, etc, among other things). We rarely talked about politics, but things adjacent to politics certainly did come up.

So I don't particularly care what my kids teachers' political views are, I just expect them to teach facts and help students draw their own conclusions. I personally consider myself a left leaning libertarian (in favor of a solid social safety net, loose social policies, balanced budgets, and low taxes), and that's a mix of my formal education and home life, as well as other interactions with interesting people.

Conservatives make the left-leaning academics thing into a big issue, but it's really not. The real issue is that teachers are underpaid, so we're not attracting a diverse enough set of teachers. My dad wanted to be a teacher (got a teaching degree and taught for a year), but the income wasn't enough so he went back and got a degree in engineering. That's a pretty serious problem, and it's especially bad in my (very conservative) area since most teachers are women who have husbands who have better paying jobs, which implies that teaching isn't a viable career for many. We're limiting our pool to people who are okay with a crappy salary.

That said, it's disingenuous to say that there's no political bias in schools. The studies indicate otherwise. However, it's a mostly unimportant detail.