President Donald Trump’s latest tariffs on Canadian goods have created a problem for lawmakers who want Congress to challenge them: the legislative shortcut used against an earlier round of Canada tariffs is no longer available. The difference comes down to the law Trump chose.
The earlier tariffs were tied to emergency powers that gave Congress an expedited procedure for considering resolutions terminating the underlying emergency. The newer duties rest primarily on Section 338 of the Tariff Act of 1930, a rarely used provision without the same fast-track Senate mechanism. Congress has not lost its constitutional authority over trade, but opponents of the tariffs now face the slower machinery of committees, leadership decisions, ordinary legislation and potentially a presidential veto. That procedural change could matter almost as much as the tariff rates themselves.
The Old Senate Shortcut Does Not Apply This Time
When Trump imposed tariffs on Canadian goods under the International Emergency Economic Powers Act in 2025, senators had an unusual procedural advantage. Because those duties were connected to a declared national emergency, lawmakers could use the National Emergencies Act to introduce a joint resolution terminating that emergency. The law contains expedited procedures requiring committees and the chambers to deal with qualifying resolutions within specified periods rather than simply leaving them untouched indefinitely.
That framework gave individual senators considerably more leverage over whether the issue reached the floor. Sen. Tim Kaine, a Virginia Democrat who helped lead previous efforts against the Canada tariffs, told Semafor that the other tariff statutes being used now do not contain the same privileged motion that allowed a senator to force action. That does not make a congressional response impossible. It does mean tariff opponents can no longer rely on the statutory clock and procedural protections that turned earlier resolutions into difficult votes for Senate leaders to avoid.
Section 338 Creates a Very Different Procedural Battlefield
The new tariffs rely on Section 338 of the Tariff Act of 1930, codified at 19 U.S.C. §1338. The statute authorizes a president, after making specified findings involving discrimination against U.S. commerce, to impose additional duties designed to offset that disadvantage. Those duties can reach as high as 50 per cent. The law generally provides for a 30-day period between the proclamation and collection of the additional tariff.
Section 338 gives the executive branch other significant tools as well. If the president finds that the foreign country continues or increases the alleged discrimination after tariffs are imposed, the statute permits certain imports to be excluded altogether. The Congressional Research Service reported in September that Trump’s actions against Canada marked the first time a president had expressly cited Section 338 to impose tariffs. The administration later used the statute again to announce import exclusions involving certain Canadian products, with those exclusions scheduled to take effect September 29. Unlike the National Emergencies Act, however, Section 338 contains no equivalent expedited congressional termination procedure.
The 2025 Canada Vote Shows What Congress Could Do Under Emergency Law
The practical difference is visible in what happened on April 2, 2025. The Senate voted 51-48 for S.J.Res. 37, a measure that would have terminated the national emergency Trump had invoked in connection with tariffs on Canadian imports. Four Republican senators — Susan Collins, Mitch McConnell, Lisa Murkowski and Rand Paul — joined Democrats in supporting the resolution. The official Senate roll call confirms both the 51-48 result and the resolution’s passage.
The measure did not ultimately eliminate the tariffs because Senate approval alone was insufficient; the House also had to act, and a successful resolution would have faced presidential presentment. Still, the vote demonstrated the importance of privileged procedures. Senators who wanted a recorded vote could obtain one even without the cooperation normally required from the majority leadership. A similar mechanism was used for other emergency-based tariff resolutions later in 2025. The current Section 338 fight begins from a different position: opponents must first navigate the ordinary legislative process before they can even recreate that kind of floor confrontation.
Ordinary Bills Can Still Challenge the Tariffs — but Committees Matter More
Congress retains broad constitutional authority over tariffs and foreign commerce, and lawmakers have already introduced legislation aimed at the new duties. On September 14, Senate Democratic Leader Chuck Schumer and a group of Democratic and independent senators introduced S. 5390, the End Trump’s Tariff Tax Act. Government Publishing Office records show that the measure was read twice and referred to the Senate Finance Committee. It would terminate and refund specified tariff duties and address several statutory authorities used by the administration.
Sens. Kirsten Gillibrand and Peter Welch have separately introduced the BAD DEAL Act, which would repeal Section 338 and provide refunds for duties collected under that authority. The important procedural point is what happens after introduction. Without a privileged mechanism, bills can remain in committee unless committee leaders, Senate leadership or a sufficiently broad coalition creates another path forward. The Finance Committee is currently chaired by Republican Sen. Mike Crapo. Kaine described that distinction plainly: ordinary tariff bills can be written, but the committee process gives the majority substantially more control over whether they advance.
Even a Floor Vote Would Not Automatically End the Tariffs
Losing the privileged route changes the ability to force a vote, but another hurdle existed even under the old system: presidential power. Legislation or a joint resolution that passes both chambers generally must be presented to the president. If Trump vetoed legislation overturning tariffs imposed by his administration, Congress would need two-thirds support in both the House and Senate to override that veto under Article I, Section 7 of the Constitution.
That distinction is important because the earlier emergency-law mechanism guaranteed procedural opportunities; it never guaranteed that Congress could enact a reversal over presidential opposition. A simple Senate majority could generate a politically significant vote, but permanently changing tariff policy could require support from a much larger bipartisan coalition. Under Section 338, opponents face both challenges in sequence. They must first get legislation through the ordinary committee and floor process, then obtain passage in both chambers, and finally confront the possibility of a presidential veto. The procedural route has therefore become longer even though Congress retains the legal power to rewrite or repeal the underlying tariff authority.
The Administration Says the Tariffs Answer Canadian Discrimination
The White House argues that Section 338 fits the dispute because Canada has disadvantaged specific American exports. Its July proclamations targeted issues involving alcoholic beverages, dairy and motor vehicles. The administration said provincial restrictions on American alcohol, differences in dairy tariff-rate-quota treatment and measures affecting U.S. vehicles placed American commerce at a disadvantage compared with competitors. Those are administration findings and remain disputed by Canadian officials and some trade-law specialists rather than uncontested conclusions.
Trump initially announced additional duties of 50 per cent on covered Canadian products. After a brief three-day suspension during negotiations, the tariffs took effect on August 22. The administration subsequently revised product coverage and announced import bans on certain Canadian products after Canada imposed countermeasures. Section 338 allows the president to modify, suspend or revoke proclamations and, in specified circumstances, move from tariffs to exclusions. That flexibility gives the executive branch several ways to change the policy without waiting for Congress, while congressional opponents must work through a substantially more structured legislative process.
Canada’s Retaliation Raises the Economic Stakes
The procedural debate in Washington is unfolding alongside a much larger commercial relationship. U.S. Trade Representative data show that U.S.-Canada goods and services trade totalled an estimated US$872.3 billion in 2025, including roughly US$715.5 billion in goods trade. For Canadian exporters, the U.S. remains especially important: Statistics Canada reported that 71.7 per cent of Canadian merchandise exports went to the United States in 2025, even after that share fell from 75.9 per cent a year earlier.
Ottawa answered the latest U.S. action with counter-tariffs of 15, 25 and 50 per cent that took effect September 8 on C$27.6 billion of U.S. imports. The targeted categories include steel, dairy products, appliances, agricultural equipment, pulp and paper, and electronics. That means the congressional procedure is not merely an institutional argument. A manufacturer buying cross-border inputs, a farmer selling into Canada or a retailer depending on imported goods can experience tariff changes through higher landed costs, altered sourcing decisions and uncertainty over whether another escalation or exemption is coming.
Pressure Can Still Build Outside a Privileged Senate Resolution
Members of both parties have raised concerns about aspects of the Canada dispute, although they differ sharply over the administration’s broader tariff strategy. Reuters reported in September that Republican Sen. Susan Collins of Maine had criticized the Canada tariffs and advocated for industry relief, while other Republicans continued to defend Trump’s trade approach. The White House maintains that the measures protect U.S. workers and exporters by responding to Canadian trade practices that it considers discriminatory.
Those divisions can still influence legislation, oversight hearings, requests for exclusions and negotiations even without an automatic floor vote. They simply do not guarantee that a repeal measure will reach the Senate floor. The Congressional Research Service has identified several options available to lawmakers, including repealing or modifying Section 338, requiring congressional approval for some tariff actions and using the U.S.-Mexico-Canada Agreement review process to influence trade policy. In other words, Congress retains several pressure points. What has changed is the ability of a single senator or small bipartisan group to place the issue on a fast procedural track.
Courts and Negotiations Remain Separate Paths to Changing the Policy
Congress is also not the only institution capable of reshaping the tariff landscape. In February 2026, the U.S. Supreme Court ruled that the International Emergency Economic Powers Act did not authorize the sweeping tariffs Trump had imposed under that statute. The administration responded by turning to other trade laws, including Section 338 for the Canada measures. Section 338 is much older and has little judicial history involving presidential tariffs, creating legal questions that trade lawyers have said could eventually reach the courts. Those arguments remain unresolved, and the administration maintains that its actions fall within the statute.
Diplomacy provides another route. Section 338 itself allows the president to suspend, revoke, supplement or amend a proclamation when the public interest warrants it, meaning a negotiated settlement could change tariff treatment without Congress passing a repeal bill. For the immediate future, the concrete developments to watch are committee action on tariff legislation, any further White House modifications, implementation of the September 29 import exclusions, possible litigation and renewed U.S.-Canada negotiations. The Senate shortcut may be gone, but the dispute still has several institutional paths through which the policy can change.
