Mexico is paying close attention to the U.S. midterm elections on Nov. 3. A change in control of Congress would not put a Democrat in the White House or end the pressures on Mexico over trade, migration and security. It would, however, change who can demand answers, control hearings and shape the terms of any lasting agreement. For a country accustomed to dealing directly with the U.S. executive branch, that would be a consequential shift. Democrats have a plausible path to the House, while the Senate remains uncertain.

A Democratic House could summon officials, investigate decisions and write spending bills. A Senate victory would give the party more leverage over legislation and appointments. The White House would still direct U.S. negotiations through January 2029, even as the next presidential race begins to shape political incentives. The first test will be the U.S.-Mexico-Canada Agreement. At the July joint review, Washington declined to extend the agreement in its current form. The agreement remains in force, with annual reviews ahead unless the three governments agree to extend it.

Meanwhile, the U.S. and Mexican governments are trying to reach a bilateral understanding before the election. Mexico wants relief from U.S. tariffs on steel, aluminum and automobiles; Washington is pressing for changes that benefit American producers and narrow its trade deficit. An announcement before November could resolve some disputes but would leave essential questions unanswered. Would Canada be brought back into a durable trilateral arrangement? Which concessions can the White House deliver, and which changes would require Congress to amend U.S. law?

Those questions would land on Capitol Hill in January. The House Ways and Means Committee would be the place to start. Its Democrats regard the U.S.-Mexico-Canada Agreement as a source of stability and have criticized the administration’s use of tariffs against close partners.

If their party wins the House, expect closer scrutiny of the negotiations and a stronger insistence on consultation. But Mexico should not mistake that for an invitation to relax. Ways and Means Democrats want tougher labor and environmental enforcement as well as secure supply chains. Across the aisle, Republicans have pressed Mexico over energy policies and loopholes that allow goods from outside North America to claim regional benefits.

The Senate Finance Committee would matter just as much for any major trade legislation. A proposal from its Democratic side would restore more congressional authority over tariffs and binding trade agreements. Whether or not Democrats win the Senate, there is a constituency in Congress for a trade relationship that gives businesses greater predictability while demanding that Mexico fulfill its commitments. A divided Congress could make a wholesale rewrite harder, but oversight of the existing agreement could grow more intense.

Money is the next lever. House Appropriations would influence funding for customs facilities, border inspection, anti-fentanyl efforts and cooperation between agencies. Its Homeland Security subcommittee brings the interests of border communities into decisions about staffing, inspection technology and the movement of legitimate commerce. A Democratic House could write different priorities into spending bills, although the Senate and president would still have to agree to enact them. That makes bipartisan support for practical border improvements essential.

Security policy could produce the sharpest public disagreements. A Democratic House Homeland Security Committee would be more likely to question how the administration conducts immigration enforcement and works with Mexico against fentanyl trafficking. House Foreign Affairs, including its Western Hemisphere subcommittee, would scrutinize the diplomatic consequences of threats to use force inside Mexico.

House Democrats have already warned against unilateral military action without Mexico’s consent and congressional authorization. That stance does not mean less interest in stopping fentanyl. It points toward a fight over methods, sovereignty and whether cooperation is producing results. There is, however, one area where a change of majority may alter the language more than the underlying demand: China. Both parties worry about Chinese investment and inputs entering North American supply chains through Mexico.

The House committee focused on China would continue to press questions about ownership, traceability and strategic materials if the next House renews its mandate. The U.S. and Mexico have already announced a critical minerals action plan. Mexico will be judged on whether it can turn that cooperation into credible rules, processing capacity and reliable infrastructure. Energy poses another test. Republicans emphasize market access for U.S. investors, while Democrats may emphasize environmental standards and clean power.

Both will ask whether Mexico can supply reliable electricity to sustain North American manufacturing. Mexico, therefore, needs a strategy for Congress as well as the White House. That means engaging trade and spending committees, members from manufacturing and border states, labor and business groups and governors whose economies depend on cross-border production. It also means arriving with evidence: measurable progress at customs, credible action against criminal networks, enforceable labor commitments and a convincing plan to supply the energy and water that new industry requires.

The midterms could give Mexico more allies in Washington who value a stable North American partnership. They could also give its critics more platforms from which to demand change. Mexico should prepare to answer to more of Washington, more often and in public. Duncan Wood, Ph.D. is CEO of Hurst International Consulting and a fellow at the Wilson Center.

Ivan Zapien is a partner in Global Regulatory Affairs at Hogan Lovells Cadwalader.