Commentary This is the second in a three part series exploring issues raised by former President Donald Trump’s lawsuit against Twitter. The first essay discussed a reason for suing that Trump does not allege, but probably should: When social media companies ban ordinary political discussion, they abuse their immunity under Section 230 of the Communications Decency Act. Congress bestowed that immunity only to enable parents to protect children, not to authorize social media to impose their biases on the rest of us. This installment focuses on Trump’s claims that Twitter’s censorship, and Section 230, violate the First Amendment and are therefore unconstitutional. The Constitution grants Congress power to “regulate Commerce … among the several States.” The Constitution’s framers wrote for the ages and they knew about technological change. By selecting the word “Commerce” (rather than, say, “trade by barge or wagon”), they covered commercial activity not yet invented. Congress exercised …