For “big pharma,” a lion’s den might seem more hospitable than the Maine Legislature this year. The animus begins at the top, in the office of Senate President Troy Jackson, a fifth-generation logger from Aroostook County on the Canadian border. Jackson isn’t shy about much, and that includes his feelings about drug companies and the prices they charge his Maine constituents. Drugmakers have been gouging “people since Christ,” Jackson, a Democrat, said — using a more colorful verb — during an interview last month.