Fails to tech American exceptionalism does not mean ignoring genocide.

I lived in Texas for years, and nearly every white person I met had the mindset, "You can't hold us responsible for our grandparent's actions,"

This isn't just Texas. Nearly the entire educated world holds this opinion. No person is responsible for things their far removed ancestors did.

Now, these republicans may be different, as I suspect they are arguing for classes that teach only how good the US is rather than a neutral view, but they have a very solid point in that classes DO need to teach the good things the US accomplishes and manages to do. History should be about informing, not pushing an agenda, not making people think differently outside of giving them more information. Topics covered should be done so based on their effect and prevalence to history and our modern state of affairs. And that isn't a coverup for saying "the trail of tears isn't part of US history" because it is, but I can very well see a history class going south very rapidly with a teacher who wants to do nothing but lecture about how horrible the USA is and all the horrible things we have done, without actually teaching the history of it.

When a large group is all saying something, they might have a reason for saying it. It means that something in the presentation of information is making people feel as if they are being lectured too about how horrible they are for these things in the past.

People don't say things for no reason. You can't just say "all of you saying this are wrong" and move on, there is some root issue that has to be treated differently for attitudes to change, otherwise people just end up smashing their heads against brick walls all day and accomplishing nothing.

Racial and national sins exist.

Mind elaborating on this statement?