Labor leaders in Maine say the resilience of the Hostess workers on the picket line at the company’s Biddeford plant, which is in the process of being shut down after the company on Friday said it would liquidate the business, gives them inspiration in the face of what they believe have been ongoing efforts — by politicians, including Gov. Paul LePage, and corporate investors — to reduce union influence. Bakers’ union officials and their supporters say also that the demise of Hostess Brands Inc., which failed to convince striking workers to return to their jobs, is a warning sign for...