God and guns vs big structural change.
The GOP has successfully convinced the base that if Dems are in power, a teacher will hand their daughter condoms to go have sex in the school bathroom, and the nurse will be giving out abortion pills. They have successfully convinced the base that if Dems are in power, 2A will be repealed and the government will come take their guns away.
This is completely untrue, but they keep voting GOP, thus the Dems don't have the power to do it, this it doesn't happen. Self fulfilling prophecy.
Meanwhile, Dems have unsuccessfully sold the base on "big structural change" being the answer to all society's ills. It is, but they have precious few actual wins in that area, because big structural change needs broad based appeal to work, and when they reach across the aisle to get it done, that big change gets watered down to the point it has virtually no effect. Even things like ACA, where it institutes a big change that most actual voters like, the GOP finds a way to sell it as government control to the base, while using the courts to dismantle it piece by piece.