Tensions over pro-Palestinian protests at Columbia University, and campuses across the US, continued to rise on Wednesday as Mike Johnson, the Republican House speaker, prepared to visit the New York institution to address what he called “virulent antisemitism” at colleges nationwide. The demonstrations, which began last week after students at Columbia set up encampments calling for the university to divest from weapons manufacturers with ties to Israel, have swept to campuses across the country, with mass suspensions and arrests of students. As temperatures rose, Kathy Hochul, the Democratic governor of New York, called Johnson’s trip “divisive”, while Democratic congresswoman Alexandria...