More than three dozen members of the US Congress have reported suspicious envelopes containing white powder, prompting office evacuations and a federal investigation ahead of the November 3 midterm elections. The latest case involved Virginia Democratic Representative Suhas Subramanyam. His district office in Leesburg was evacuated on Monday after an envelope containing an unknown substance arrived. Subramanyam said staff cleared the office quickly. He condemned the incident and said political intimidation had no place in the country.…