Eight days of rafting down the Colorado River in the Grand Canyon with my daughter promised to be an exceptional experience. Introducing myself to a fellow voyager, a Texan, I joked that surely Texas wasn’t really planning to secede, because it would be a pain to have to obtain a visa to visit Austin. This didn’t seem to go over well. Perhaps I had overreached. I retreated for the rest of the trip into an affable neutrality. Turns out, others did the same. There would be an occasional dig at President Joe Biden’s senility or a whisper about former President Donald Trump’s criminality, but soon, a taboo began to govern the otherwise warm and caring sociability of our group. Even though we were a diverse assembly of 30 people, gay and straight, black and white, ages 9 to 81, a freewheeling dialogue about politics or religion in the group at large was strictly off the conversational table. In spite of us all being citizens of one country, floating down wild rapids together in our…