Senators Make Modest Moves To Reclaim Tariff Powers From Trump

A small but growing bipartisan movement in the Senate is pushing back against the president's imposition of tariffs, but there's plenty of room to go further.

On Wednesday, President Donald Trump made good on his promise to impose tariffs on nearly every nation, principality, and uninhabited island on the planet—an event he dubbed "Liberation Day." The measure would place 10-percent tariffs across the board, with additional duties imposed on dozens of countries next week. Markets have plummeted in response.

There is now a small but growing bipartisan movement in the U.S. Senate to narrow or undo Trump's tariffs. While encouraging, the efforts so far are much too modest, especially since the power to impose taxes and tariffs belongs to Congress in the first place.

Hours after the announcement on Wednesday, the U.S. Senate passed a resolution from Sen. Rand Paul (R–Ky.) that would undo tariffs Trump had previously imposed on Canada. Trump justified that move at the time through an emergency declaration about "the extraordinary threat posed by illegal aliens and drugs, including deadly fentanyl." Under the 1977 International Emergency Economic Powers Act (IEEPA), the president can unilaterally impose tariffs in order to address "any unusual and extraordinary threat…to the national security, foreign policy, or economy of the United States, if the President declares a national emergency with respect to such threat."

Paul's Senate resolution would remove Canada from the declaration, as less than 1 percent of all fentanyl seized in the U.S. comes across the northern border. The resolution "faces an uncertain future in the Republican-controlled House and a near-certain veto if it reaches Trump's desk," Reason's Eric Boehm wrote, "but it also represents a small glimmer of hope, as it is the first serious attempt by Congress at limiting the president's ability to smash free trade."

Sen. Tim Kaine (D–Va.), who co-sponsored the measure, also told Semafor's Eleanor Mueller on Thursday that he would be drafting a motion of disapproval targeting Trump's 10-percent "across-the-board" tariffs.

That same day, Sens. Chuck Grassley (R–Iowa) and Maria Cantwell (D–Wash.) introduced the Trade Review Act of 2025. The bill would amend the Trade Act of 1974 to require the president to notify Congress within 48 hours of "imposing or increasing a duty with respect to an article imported into the United States." That notification must include both "an explanation of the reasoning" and "an assessment of the potential impact of imposing or increasing the duty on United States businesses and consumers." After that point, the tariff "shall remain in effect for a period of not more than 60 days, unless there is enacted into law a joint resolution of approval."

At first glance, this seems like a welcome constraint on the president. But it's ultimately a feckless gesture that concedes the president's power to unilaterally impose tariffs in direct defiance of the Constitution.

For one, the bill explicitly states that it applies only to the Trade Powers Act, which Trump used in his first term to impose tariffs on China and requires a review process and congressional approval. But it doesn't touch the IEEPA, which Trump has already used to assign tariffs with nothing more than a stroke of his Sharpie.

Further, Article I, Section 8 of the Constitution gives Congress "Power To lay and collect Taxes, Duties, Imposts and Excises." But over the previous century or so, Congress has repeatedly abdicated its powers to the executive branch—including the power to impose tariffs.

"Congress delegated large amounts of its international economic authority to the executive branch in 1934 and through subsequent laws, under the prevailing assumption that the president was far less likely than Congress to be influenced by parochial interests and rent-seeking lobbyists," Clark Packard and Scott Lincicome of the Cato Institute wrote in October 2024. "The only sure way to limit the risk of future unilateral tariffs therefore rests with Congress acting to reclaim some of its constitutional trade powers."

The Grassley–Cantwell bill would seem like it was doing just that. But a bill setting a time limit on the president's power to impose tariffs of his own is effectively conceding that the president has that power in the first place, when the Constitution explicitly said the opposite.

A similar scenario played out more than five decades ago. In 1973, Congress passed the War Powers Resolution as an explicit check on the president's powers regarding "the introduction of United States Armed Forces into hostilities, or into situations where imminent involvement in hostilities is clearly indicated by the circumstances, and to the continued use of such forces in hostilities or in such situations."

Much like the Grassley–Cantwell bill, the War Powers Resolution required that "in the absence of a declaration of war, in any case in which United States Armed Forces are introduced," the president "within 48 hours" must notify both houses of Congresses in writing, detailing why troops were deployed and "the estimated scope and duration of the hostilities or involvement." Then, absent a congressional declaration of war, the president would have 60 days before he had to begin withdrawing troops.

Congress passed the resolution at the tail end of the Vietnam War, amid revelations that President Richard Nixon had bombed Cambodia without congressional approval or even notification. Nixon actually vetoed the resolution, but it became law anyway by two-thirds votes in the House and Senate.

But the Constitution explicitly places the power to declare war with Congress, not the president. The War Powers Resolution implicitly affirmed the president had some authority to deploy troops even without a declaration of war, directly contradicting the Constitution.

"In the post-Cold War world, Presidents have continued to commit U.S. Armed Forces into potential hostilities, sometimes without a specific authorization from Congress," according to a 2004 report by the Congressional Research Service. Even then, presidents can easily circumvent the 60-day limit: "From 1975 through 2003, Presidents have submitted 111 reports as the result of the War Powers Resolution, but only one…cited section 4(a)(1) which triggers the time limit, and in this case the military action was completed and U.S. armed forces had disengaged from the area of conflict when the report was made."

By the same token, the Trade Review Act implicitly allows the president to impose tariffs on a whim and keep them in place for 60-day increments.

Senators like Paul, Kaine, Grassley, and Cantwell should be lauded for their efforts to claw back their constitutionally appropriated power of the purse. But more than that, they should be encouraged to go even further. The framers imbued taxation powers with Congress, a body currently comprised of 535 members; instilling that power in a single person clearly undercuts their intent.