Public schools have been increasingly focused on politics. It's scary even if you agree with the general ideas. You hear kids repeating mantras and slogans with very little understanding. And it's all reinforced in popular culture/entertainment.
I think you underestimate how often the kids are passing along political mantras and overestimate how often teachers are. Go look at GenZ TikTok and how it is massively political and in such a way that there is no chance teachers are driving it.
I assure you kids don’t care about the quietly muttered opinion of their social studies teacher but are much more informed by their siblings, peers, and parents. The opinions get shared at school and absorbed by developing minds that don’t handle politics with much nuance largely because the relevant history of politics is never taught to them in school, cutting off at Vietnam War at the latest. And why is recent history eschewed in favor of covering the 1780s in boring detail? The desire to keep politics out of schools. And to some extent, the desire of Texas purchasers of textbooks to promote a reactionary view of the country. Covering the AIDS epidemic just leads to complaints about making Reagan out to be a villain or that teachers are corrupting kids with homosexualism. If kids repeat dumb slogans, can we blame them when they don’t have a knowledge of any modern political history except what they’ve gleaned from their parents cable news of choice?
I am from Brazil, and I don't intend to put my kids in school if I can (here it is illegal to homeschool, prison time for parents and all, I am hoping to get out of the country if the needed laws don't pass when I have kids).
And a good reason for it, is the amount of bullshit fed to me and my friends by the shovelfulls, when I was a teenager I believed all adults I knew except schoolteachers were evil, because they didn't like Mao, Stalin and Che Guevara, I was taught that Pol Pot was a hero, literally, only after I was out of the school system that I could finally learn what these people actaully did.
Then over the years I picked more and more on what sort of stuff school taught me wrong, there were a few things in harder sciences, but when it is social stuff, school was a disaster, lie after a lie, sadly some of theses lies remain pervasive in society (for example many people in my country believe the monarchy was pro-slavery, despite documents that exist that show that the monarchs themselves wanted slavery abolished, and that when they DID abolish slavery, the coup that ended monarchy was sponsored by the biggest former slaveowners).
It acts as a shield because, no matter how useless the teacher is as an educator, any criticism of them becomes political criticism.
I definitely think that no single activism group or "area" should get an outsized influence in education. Certainly it would be irresponsible for teachers or school boards to simply take an given activists group's curriculum or material and apply them as is.
While I understand the hesitancy, especially in the early childhood context, I do wonder what you how educators should approach topical things like black lives matter?