U.S. Immigration and Customs Enforcement has detained or deported several foreigners across the country who are also prominent immigration activists, prompting accusations from advocates that the Trump administration is improperly targeting political opponents. Detention Watch Network, a nonprofit that tracks immigration enforcement, said this week that several activists have been targeted recently, including Maru Mora Villalpando in Washington state, Eliseo Jurado in Colorado, and New York immigrant leaders Jean Montrevil and Ravi Ragbir. “They’re trying to intimidate people,” said Rep. Jerry Nadler (D-N.Y.), the ranking Democrat of the House Judiciary Committee. “These are well-known activists who’ve been here for decades,...