WASHINGTON (AP) — President Barack Obama's choice to be the No. 2 official at the Homeland Security Department is under investigation for his role in helping a company run by a brother of former Secretary of State Hillary Rodham Clinton, The Associated Press has learned. Alejandro Mayorkas, director of U.S. Citizenship and Immigration Services, is being investigated for his role in helping the company secure an international investor visa for a Chinese executive, according to congressional officials briefed on the investigation. The officials spoke only on the condition of anonymity because they were not authorized to release details of the...