That history was taught me as a child in Texas...and it said all that needed to be said IMHO.
Damn straight. When I was in Jr. High, we called it "Texas History".
--and it's the same program that Texas is using now. It's what I've just gone over with my daughters per a State of Texas home-schooling program.
A couple of things about this "study" are beginning to smell. One is that it's not available for us to download so we can make our own evaluation. The other is that there's a different study that is available, also this year and also by the same institute, ranked Texas at the top.
Since they think that Texas still belongs to Mexico, then that should suffice