Dozens of New York Democrats were tricked by a troll Twitter account into condemning comments Democratic Rep. Maxine Waters made in 2018 about harassing Trump officials in public. In June 2018, Ms. Waters notoriously called on her supporters to harass members of the Trump administration in response to its separation of illegal immigrant families at the border, saying, “If you see anybody from that Cabinet in a restaurant, in a department store, at a gasoline station, you get out and you create a crowd. And you push back on them. And you tell them they’re not welcome anymore, anywhere.” On...