Donald Trump’s tariff policies suffered their strongest political blow yet with the Republican-led U.S. House passing legislation aimed at ending the president’s levies on Canadian imports.

The vote on February 11 represents an increase in political pressure to change course on Trump’s signature economic policy just months before the midterm elections, including by forcing swing-district Republicans affected by the tariffs to weigh when or if to cross the president by voting against his agenda.

The vote also signals a growing anxiety over the White House’s economic agenda before elections that are expected to focus heavily on affordability. Democrats were quick to attack the Republicans who voted to protect the tariffs, blaming them for shielding policies that increase the cost of living for their voters.

While Trump is almost certain to veto any bill calling for a repeal of his tariff agenda, making it unlikely the measure will ever become law, defections from six Republicans alongside opposition from nearly all Democrats underscore his increasingly tenuous hold on the narrow House majority. 

Senate Majority Leader John Thune told reporters on February 12 that he expects the Senate to vote on the House resolution and “it probably ends up with the same outcome.”

Republicans are fighting to maintain control of both the House and Senate this November, a job made more difficult by the president’s slipping approval in polls on the economy and immigration. 

Read More: Trump Immigration Policy ‘Wreaking Havoc’ on U.S. Food Production, Say Former Agriculture Leaders

Trump has a personal interest in holding onto Republican majorities in Congress — it makes it easier for him to pass legislation he favors, and would shield his administration from congressional investigations.

Democrats have outperformed expectations in a series of elections over the last several months, including the Miami mayoral race and the New Jersey and Virginia governor’s races. In recent weeks, a solid Republican Texas state Senate seat flipped blue in a 31-point swing toward Democrats. 

The measure’s passage also comes as Trump privately weighs quitting the U.S.-Mexico-Canada trade pact he signed during his first term, a decision that would worsen trade tensions in North America. About 80% of goods imported from Canada meet USMCA criteria, and are exempted from tariffs. 

Read More: Trump Threatens to Block Opening of Cross-Border Canadian Bridge

Primary election threat

Before the elections in November, though, will come a series of House and Senate primary races, in which voters decide which candidates will represent their parties. Trump, whose primary endorsements weigh heavily, made clear even as the votes were being cast on the evening of February 11 that there would be political consequences for any Republicans who crossed him on the issue.

“Any Republican, in the House or the Senate, that votes against TARIFFS will seriously suffer the consequences come Election time, and that includes Primaries!” Trump wrote in a social media post. “TARIFFS have given us Economic and National Security, and no Republican should be responsible for destroying this privilege.”

Republicans Thomas Massie of Kentucky, Don Bacon of Nebraska, Kevin Kiley of California, Jeff Hurd of Colorado, Dan Newhouse of Washington State and Brian Fitzpatrick of Pennsylvania broke with their party to join Democrats in passing the bill. 

Newhouse told reporters later that “the trading relationships between Canada and the state of Washington is pretty intertwined with a high value of exports and imports. There are a lot of Canadian employers in my district that employ a lot of people.” 

That the vote happened at all represented a blow to House Speaker Mike Johnson, a top Trump ally who had spearheaded a block on bringing tariff-related bills to the floor for months. That ended Tuesday when three Republicans joined Democrats in rejecting another extension of the blockade. 

Afterward, Johnson said he had met with Trump earlier on February 11, and that he understood that he could veto the measure if it were ever approved by the Senate. “It doesn’t really affect the trajectory of what he’s doing,” Johnson added. “There’s proof that his trade policy is working.”

The speaker had argued the chamber should keep the ban in place until the Supreme Court ruled on whether Trump’s global tariffs, which he put in place citing an emergency, are legal. That opinion could be released as soon as February 20. 

Chuck Schumer, the Senate Democratic leader, said “Both chambers have now rejected his phony ‘emergency’ and his fabricated trade war. The Supreme Court should take notice.”

Trump has long held that tariffs are not just a tool in and of themselves; they also strengthen his hand in negotiations with other nations when making trade deals. 

“Canada has taken advantage of the United States on Trade for many years. They are among the worst in the World to deal with, especially as it relates to our Northern Border. TARIFFS make a WIN for us, EASY. Republicans must keep it that way!” Trump said.

The Republican-controlled Senate has also voted to abandon Trump’s Brazil tariffs and emergency global duties, in addition to the Canada tariffs. 

Political pressure

However, since joint resolutions must be signed by the president to become law, or passed overwhelmingly to override a veto, it’s unlikely lawmakers can force him to abandon his signature economic policy through legislation alone. 

Representative Gregory Meeks, a New York Democrat, is expected to force other tariff-related legislation onto the floor, including measures to end the White House duties on Brazil and Mexico.

“It’s time we end the so-called national emergency, because the only emergency here is the economic one created by Trump’s tariffs,” Meeks said Wednesday. “Americans are paying more for health care and their daily essentials during an affordability crisis, all because of a manufactured emergency and one man’s ego.”