One step that goes a bit beyond buying a book is discussing it—not primarily with the end goal of selling the book but of raising awareness of real-life issues. If someone hears that a book on climate change was banned & their next thought is "hey, my friend told me that book has good points," they don't necessarily buy or read it, but maybe they start to be more attentive to climate change and also realize that book banning is bad. I agree reading & writing isn't the whole answer, but, for those of us who are going to read/write anyway, 🙋‍♂️ discussing the books we buy can help the author's message get out. "Reading visibly" can be a small political act, IMO. Have the book on your lap on the train. Whatever seems constructive.