Massachusetts Attorney General Maura Healey is urging Republican Congressman Lamar Smith to withdraw his committee’s subpoena for documents related to her Exxon Mobil investigation. Healey sent a 10-page letter to Smith Wednesday arguing the House Committee on Science , Space and Technology has no authority over her probe into whether Exxon Mobil misled Massachusetts consumers and investors about the impact of burning fossil fuels on the environment and the impact of climate change on the company’s business.