WASHINGTON (Reuters Breakingviews) - Donald Trump’s trade war has left a mark on the U.S. electoral map. The healthy economy was a helpful running mate for Republicans in Tuesday’s midterm elections. But areas like Pennsylvania, hit by duties and retaliatory tariffs arising from the president’s import levies, were weak spots for his team.

True, Trump’s tariffs are popular in Pennsylvania’s steel country. But some areas, like the state’s seventh congressional district, are home to farmers hit by retaliatory duties and manufacturers whose costs have gone up. That helped Democrat Susan Wild, a former top legal officer for the city of Allentown, defeat Republican Marty Nothstein, a former Olympic cyclist, to win a seat in the U.S. House of Representatives where Democrats nationwide are set to win a majority.

Duties on U.S. agricultural products imposed by China and others have particularly hurt Iowa. Republican David Young, who represents the state’s third district in Congress, criticized Trump’s tariffs and even wrote an op-ed in the Des Moines Register saying they are bad for the state. But he still lost to Democrat Cindy Axne, a small business owner.

Another Republican critical of Trump’s tariffs, Congressman Steve Russell of Oklahoma, surprisingly lost to Democrat Kendra Horn. He tried to allay trade fears and toured an Anheuser-Busch Metal Container plant in his district, which is worried about the aluminum levies. Horn, a lawyer, accused him of not doing anything to stop the duties.

Other areas hurt by trade conflict still have faith in Trump, who also played to fears about illegal immigrants. The Mid Continent Nail Factory in Butler County, Missouri, which previously had 500 employees, has laid off or not replaced about 200 people since steel tariffs were imposed. But Trump overwhelmingly won that county in 2016 and residents rewarded his favored Republican Senate candidate, Josh Hawley, the state’s attorney general on Tuesday. Hawley defeated incumbent Democrat Claire McCaskill, who has been a vocal critic of the administration’s trade war.

It’s not a picture that’s entirely clear one way or the other. But certain results show how the president’s tariffs have hurt fellow Republicans, many of whom have said they would rein in Trump’s protectionist moves but have not yet done so. It’s a warning for the party that’s usually the champion of free trade to remember its roots.

CONTEXT NEWS

- The Democrats were set to win control of the 435-member U.S. House of Representatives in midterm elections held on Nov. 6. Republicans retained a majority in the Senate, where 35 of the 100 seats were contested.

(The author is a Reuters Breakingviews columnist. The opinions expressed are her own.)

(Editing by Richard Beales and Katrina Hamlin) ((gina.chon@thomsonreuters.com; Reuters Messaging: gina.chon.thomsonreuters.com@reuters.net))