I'll never forget moving to Alabama as a child and having people tell me with a straight face it's a civil war had not been about slavery. Teachers in school taught explicitly that the Confederacy was not established to uphold slavery.
I learned in school in Alabama that most slaves had been happy and well treated, and that the Confederacy was about upholding freedom from tyranny.
I don't think school is in Alabama teach that anymore, unless teachers are doing it on the sly, but I know for a fact that some of the people I grew up with down there still believe those falsehoods. And they're still teaching to their children.
Of course, when I say some I certainly don't mean all.
People who know the truth about history need to stand up for the truth. No matter what political party they belong to.