The two most important takeaways from the final presidential debate are these: First, no Republican presidential nominee should agree ever again to a debate organized by the Commission on Presidential Debates (CPD)—at least without major reforms. Second, no such candidate should ever consent to a “mainstream media” moderator. In the last presidential debate of the season the bias of Kristen Welker (NBC, MSNBC) was palpable: She repeatedly interrupted and quibbled with President Donald Trump, while presenting a much more respectful demeanor toward former Vice President Joe Biden. But far worse was her selection of topics. These seem to have been...