The GOP has been trained for several decades by lefty moles that "Education is something dominated by the left" and that it's a lost cause for the GOP to even attempt.
See also:
Organization
Pop Culture
Comedy
Music (outside of certain genres that they are actively trying to destroy)
Comics
Vidya Games
All of these are "left leaning" things and the common refrain is it's just because lefties are naturally drawn to them. That's a lie. It's gatekeeping and hard work to keep that shit lefty-centric and the righties out.
That's the main reason, I think. The Trumpian, Nu-Right, has realized that the GOP has been trained to give in to the left on all Culture War stuff and stuff that is "owned" by the left, and education is part of that. It's only now that the Nu-Right is giving the left a serious bloody nose that the Right in general is realizing that the left has no fucking idea how to fight a culture war, not anymore, and their entire existence revolves around the other side admitting that the left is correct and awesome and perfect and unquestionable. For example, the "fetal heartbeat" killshot for state sanctioned baby murder. The right is supposed to flinch whenever the leftyfags even make a motion to punch at them, that's the "rule."