The journalists at CNN, MSNBC, the Washington Post and the New York Times and, broadly speaking, the elected officials and paid operatives of the Democratic Party—almost all of these people agree on the issues of the day: women’s rights, abortion, gay marriage and other LGBTQ issues, Black Lives Matter, gun control, immigration, the border wall, family separation at the U.S.-Mexican border, Russian collusion, Brett Kavanaugh’s fitness and so on. They agree, above all, in opposing and loathing Donald Trump.

MSNBC’s “Morning Joe” unfolds each weekday morning as a relentless, ritualized denunciation of Mr. Trump and all his works. With almost hilarious single-mindedness, the program’s repertory company addresses itself to the work of discrediting and—they hope—one day ousting the president.

It will be fatal to Democrats’ chances in 2020 to encourage the suspicion they won’t tolerate points of view that differ from progressive orthodoxy. Unbiased viewers know that Fox employs many credible journalists: Bret Baier, Martha McCallum and Chris Wallace, for example.