Maybe start with low-grade English and math textbooks? If the book's editor is a bit savvy about hot buttons, I'd guess that rather few cultural warriors have strong feelings about adding fractions, distinguishing adverbs from adjectives, etc. And "eagerly engaging" the anti-big-government types on the tedious details of such subjects might soon drive them away.

(No, this approach could not be extended to American history, science, etc. But some good could be done.)