WASHINGTON — The Trump administration is expanding tariff exemptions to more Canadian products, a move that may help boost Republican Senator Susan Collins’ reelection campaign in Maine.

Collins announced in a statement 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 specialized equipment, packaging materials, and other products from Canada that are either unavailable from American suppliers or cannot be replaced without incurring significant expense,” she said.

President Donald Trump will amend the tariffs to add new ones to replace the exclusions so that the overall tariff impact is unchanged, a U.S.…