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Democrats regained control of the House of Representatives in the midterm elections last November, flipping 40 seats that had been previously held by Republicans.

A yearlong trade dispute between the Trump administration and China may have contributed to at least five of those losses, according to a new working paper.

"Trump's trade war may have been a significant contributor to the Republican Party's weak showing in the 2018 House elections," the researchers said.

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Democrats regained control of the House of Representatives in the midterm elections last November, flipping 40 seats that had been previously held by Republicans. A yearlong trade dispute President Donald Trump ignited with China may have contributed to at least five of those losses, according to a new working paper.

Republican support appeared to take a particular hit from Chinese tariffs on US farm goods, which were levied last summer to retaliate against the the Trump administration. Farmers have seen prices of soybeans and other agricultural exports drop sharply since then, testing the loyalty of a key constituency on the right.

"Trump's trade war may have been a significant contributor to the Republican Party's weak showing in the 2018 House elections," economists Emily Blanchard, Chad Bown and Davin Chor said.

In counties where employment was concentrated in products affected by those measures, Republican candidates lost vote share. That was particularly the case in swing counties, which saw the slimmest margins in the 2016 presidential election.

The Trump administration has sought to fight off tariff backlash, which has grown increasingly evident among Republican lawmakers and voters, through a $28 billion bailout program. The associated subsidy payments to farmers shored up broad support, according to the paper, but only in certain areas of the country.

"The agricultural subsidies did not appear to prevent the loss of any House seats, despite the estimated positive average effect on overall Republican support," the authors said. "This difference is consistent with the fact that the farm payouts went to a narrow set of rural counties that already tend to vote Republican."

A separate working paper released in March reached similar conclusions, offering further evidence that retaliatory tariffs have had the most pronounced effects in GOP-leaning counties.

"Workers in very Republican counties bore the brunt of the costs of the trade war, in part because retaliations disproportionately targeted agricultural sectors," the paper said.

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