The Trump administration is expanding tariff exemptions to more Canadian products, a move that may help boost Republican Senator Susan Collins’ re-election campaign in Maine. Collins announced in a statement on Friday that the exemptions would apply to certain paper, plastic, machinery and seaweed products, saying they would help the state’s rural and coastal economy, including the blueberry, potato, apple and seaweed industries. “Many of our farmers and growers rely on specialised equipment,...