Commentary PITTSBURGH—Twenty years ago, Paul Carson said he never would have hesitated to speak out at a school board meeting about any issue affecting his children’s education. But one day, that changed. “I just don’t do it,” Carson told me. A physician who practices medicine in an urban Pittsburgh hospital, Carson said it has nothing to do with his being 20 years older. “It has everything to do with the culture we are navigating.” Anyone, he said, can take a video of what you say, edit it to his or her advantage, then post it on social media. Or they can just simply claim on social media that you are racist or extremist because you express an opinion outside the sensitivities of the cultural curators who define what is acceptable and what is not in our country. When Carson used a media platform in discussions about school district issues, as …