The study, commissioned by the lobbying shop for Koch Industries and conducted by consulting firm ImpactECON, looked at the potential cumulative impact of tariffs.
Senate Republicans want to vote on the U.S.-Mexico-Canada trade agreement in the lame-duck session of Congress. But they need President Trump to finalize the deal.
Tariffs levied against China accounted for $800 million in September, even though the bulk didn't take effect until the end of the month.
Democratic Sen. Elizabeth Warren had called for the Commerce inspector general to open an investigation into the exclusion process, which has come under heavy criticism.
Warren's office reviewed a sample of more than 900 steel exemption decisions made by the Department of Commerce.
Seven countries — including Mexico, Canada and the European Union — disputed U.S. tariffs on foreign steel and aluminum at a meeting of the World Trade Organization in Geneva on Monday.
Businesses say they are baffled by the decision — and fear it's another sign that trade tensions with China will not subside any time soon. Previous rounds of tariffs included a formal process for companies to request specific products be removed from the list.
The opportunity zones come with several tax advantages. Capital gains placed in a certified opportunity zone fund will not be taxed through the end of 2026 or when the investment is sold, whichever comes first.
The "Tariffs Hurt the Heartland" campaign involves reaching out to members of Congress, buying ads and hosting town hall style meetings in swing states.
Trump has suggested revenue from tariffs could be used to reduce the federal deficit, which rose to $77 billion in July.