Republicans on Capitol Hill are treading lightly around new proposals that could rein in President Trump’s unilateral tariff power, even as markets recoil from the administration’s new trade scheme. The ideas being kicked around by lawmakers — even if they could pass through Congress — would almost certainly have no support in the White House. 

Following Mr. Trump’s announcement Wednesday that he would impose a ten percent tariff on all global imports, on top of country-specific import taxes, the stock market was quick to plunge. By the end of the day on Thursday, the Dow Jones Industrial Average was down more than 1,600 points — its largest single-day drop since 2020. The S&P 500 had fallen more than 250 points and the Nasdaq was down more than 1,000 points. 

Senator Grassley unveiled a piece of legislation with a Democrat, Senator Cantwell, on Thursday morning in response to the market reaction. The bill would force Congress to vote to approve of the tariffs issued by the president within 60 days. Otherwise, the import taxes would expire. 

“For too long, Congress has delegated its clear authority to regulate interstate and foreign commerce to the executive branch,” Mr. Grassley said in a statement. “Building on my previous efforts as Finance Committee Chairman, I’m joining Senator Cantwell to introduce the bipartisan Trade Review Act of 2025 to reassert Congress’ constitutional role and ensure Congress has a voice in trade policy.”

Fellow Republicans had little to say about Mr. Grassley’s proposal that would place a limit on Mr. Trump’s tariff authority, however. When asked by the Sun if she had a position on the new bill, Senator Capito — who serves in Republican leadership — furrowed her brow and said, “I do not.” 

Senator Lankford said he was still studying the “details” of the five-page piece of legislation, though when he was explained the straightforward measure by the Sun, he declined to offer any comment. 

Senator Barrasso had a more imaginative approach. When asked about Mr. Grassley’s Trade Review Act, Mr. Barrasso went on a lengthy speech about what a great job Mr. Grassley is doing with respect to “rogue” federal judges before ducking onto an elevator. 

Besides Mr. Grassley, only two Republican lawmakers — Senator Tillis and Senator Murkowski — have so far expressed support for the measure. 

They may be forced to take an up-or-down vote on Mr. Trump’s broad tariff imposition whether they want to or not, however. Despite controlling both the House and Senate, Republicans do have to acquiesce to some joint resolutions that Democrats can push onto the floor, as Senator Kaine did on Wednesday night when four Republicans joined all Democrats to revoke Mr. Trump’s February emergency declaration that paved the way for his new Canada tariffs. 

When the House returns from its recess, the top Democrat on the Foreign Affairs Committee, Congressman Gregory Meeks, says he will put a resolution on the floor revoking Mr. Trump’s new emergency declaration. That would mean every House Republican would have to signal either approval or disapproval of the president’s global tariffs. 

“Trump just hit Americans with the largest regressive tax hike in modern history — massive tariffs on all imports,” Mr. Meeks said on Wednesday night. “His reckless policies are not only crashing markets, they will disproportionately hurt working families.”

The president’s new tariffs represent the largest import taxes imposed in more than 100 years, according to a study by the Tax Foundation last year. The Smoot-Hawley tariff of 1930 represented an average tariff rate of 20 percent for all imports. Fitch Ratings, a credit rating agency, calculated that Mr. Trump’s new tariffs average out to a 22.5 percent tax on imports. The last time the average tariff rate was that high was in 1909.