The Trump administration plans to scrutinize social media for “anti-American ideologies" when deciding to grant visa or green-card applications. U.S. Citizenship and Immigration Services, the primary agency in charge of legal immigration, said Tuesday that its officers should give significant weight to evidence that an immigrant “has any involvement in anti-American or terrorist organizations" when reviewing residency, work and visa applications. When it comes to what registers as anti-American ideology, the updated guidance points to a provision of immigration law dating back to the Cold War that prohibits immigrants from becoming U.S. citizens if they are members of communist or...