The White House is in a full-blown baby boom. Second lady Usha Vance, White House press secretary Karoline Leavitt, and Katie Miller, wife of White House Deputy Chief of Staff Stephen Miller, are all pregnant. It will be Vance’s fourth child, Leavitt’s second, and Miller’s fourth. White House deputy chief of staff James Blair and his wife, Sam, are expecting a baby come March, according to Louise Perry, writing for The Wall Street Journal. Perry notes a partisan gap in birthrates: “Conservatives have more children than liberals. They also are more likely to marry and marry younger. While Democrats are...