NEW YORK (Reuters) - Politicians in America’s Rust Belt will likely struggle to capitalize on U.S. President Donald Trump’s trade war in November’s congressional elections, with a September poll showing voters in the region are cool on the effect of tariffs.

Water flows out as a steel slab is cooled at a steel mill in Farrell, Pennsylvania, U.S., March 9, 2018. REUTERS/Aaron Josefczyk

A Reuters/Ipsos/UVA Center for Politics Poll found that a plurality of voters in Indiana, Michigan, Ohio, Pennsylvania, and Wisconsin - states in America’s industrial heartland that backed Trump in the 2016 presidential election - thought tariffs were not good for themselves or their families.

Support for tariffs among likely voters - people who have been identified as most likely to take part in the upcoming election - varied from 33 percent in Pennsylvania to 38 percent in Michigan. In all states, more were negative on tariffs, varying from 44 percent in Indiana to 50 percent in Wisconsin.

“Trade and tariffs aren’t this powerfully positive issue for the President and Republicans; if anything they are viewed as counterproductive to the people and places that elected Trump,” said John Austin, Michigan-based Nonresident Brookings Institute Senior Fellow, based on the survey and anecdotal evidence.

Trade and tariffs have become a thorny issue for congressional candidates as they seek to win votes in the mid-term elections.

On the presidential campaign trail, many Rust Belt voters cheered Trump’s criticism of international trade agreements as being bad for the United States. However, new deals have proven tough to strike.

Trump’s tariffs on imported steel and aluminum have allowed U.S. producers to raise their prices, but hiked costs for manufacturers of cars and other goods. U.S. exporters are also facing retaliatory tariffs from China and others.

While support for tariffs was more pronounced among Republicans than Democrats, the issue is not turning into an automatic slam-dunk for Republicans.

Among Republican-voting respondents in the poll, only a little over half in some Rust Belt states thought tariffs were good for their families - 53 percent in Indiana and 51 percent in Pennsylvania. It was slightly more in Ohio at 57 percent. Approval was higher in Michigan at 59 percent and Wisconsin, at 60 percent.

A poll released on Wednesday showed a majority of likely voters in Pennsylvania, Wisconsin, Ohio, Michigan and Indiana disapprove of Trump.

Indiana Republican Mike Braun, running against Democratic Senator Joe Donnelly, was quoted in the Indianapolis Star in February as saying that tariffs were a "mistake" because they provoke retaliation. Braun's campaign did not respond to a request for comment about his views on tariffs. His opponent, a pro-union Democrat who has in the past favored trade protection measures, has said he is concerned about the president's actions.

Likely-voter poll respondents were more inclined to think that international trade created jobs rather than caused job losses. Yet a majority of respondents in each state also thought international trade hurts average Americans because it keeps wages down due to the cheaper cost of foreign labor.

Chad P. Bown, a senior fellow at the Peterson Institute for International Economics in Washington, said tariffs and trade can be a misunderstood topic and it was “entirely plausible that trade is not a big part of the midterm elections.”

“I spend most of my time thinking about international trade but most people don’t,” Bown said.

Michigan and Indiana have particularly high international trade exposure, according to Moody’s credit agency, which said Michigan had international trade account for 38 percent of its gross domestic product, while Indiana had 24 percent.

The state polls were conducted online, in English, from Sept. 12 to Sept. 21. They surveyed between 1,074 and 1,181 likely voters in each of five states and weighted the responses according to the latest government population estimates.

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