Democrats Win Control of Congress. Here’s How That Could Affect U.S. Foreign Policy.

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Democrats secured a resounding victory in Tuesday’s midterms, taking both the Senate and the House of Representatives against the backdrop of the Iran war and concerns over tariffs, the economy, and the cost of living. While President Donald Trump will maintain significant control over U.S. foreign policy and tariffs, Democrats will hold the federal purse strings, chair congressional committees, and—through control of the Senate—decide which of Trump’s nominees are confirmed to key national security and diplomatic posts.

CFR experts expect the Democratic-led Congress to focus on affordability and challenge the administration over the Iran war. But they also note that the absence of a veto-proof majority will constrain Democrats’ ability to reverse Trump’s tariff policies or his approach to the Ukraine war and relations with European allies.

Below are more of their takeaways from the midterm results:

WHAT CFR EXPERTS MAKE OF IT

Rebecca Lissner is senior fellow for U.S. foreign policy and director of the Future of American Strategy Initiative at CFR.

The scale of Democrats’ victory on Tuesday came as a surprise, but voters’ focus on the nexus of foreign policy and affordability did not. Polls and CFR’s own focus groups have consistently shown the depth of Americans’ opposition to the Iran war and tariffs—two signature Trump administration policies that have proven to be both bad policy and bad politics. 

As Washington turns its attention to presidential primaries, prospective candidates will analyze these midterm results in crafting their foreign policy platforms. There is a clear opportunity for candidates to seize the anti-interventionist lane Trump once occupied but has now abandoned. So too is there an opening to parlay opposition to tariffs into an affirmative international-economic agenda that restores predictability and lowers costs. Perhaps most importantly, political aspirants must recognize that bids to restore U.S. global leadership will only sustain support if Americans feel confident that their kitchen-table concerns are being prioritized and addressed at the same time.

Rebecca Patterson is a senior fellow at CFR. She is a globally recognized investor and macro-economic researcher.

The coming Democrat-led Congress appears likely to focus on two main issues over the next two years, both with important economic implications: affordability and corruption. They will try to pass legislation to lower costs of key items—including housing, energy, and food as well as health care and drug prices. They will also push Republican colleagues to join them to end the Iran war and reduce select tariffs in the name of affordability. Congressional hearings will also include economic issues. For example, we could see companies challenged about whether tariff refunds went to customers or were used to support profit margins. 

While the presidential veto will limit what bills the new Congress can pass, a Republican minority eyeing the 2028 elections may be willing to join on certain economic issues that resonate with their constituents.

Pierre Yared is a senior fellow at CFR. He served on the White House Council of Economic Advisers during the second Trump administration.

Because tariffs are set by the president using authorities that Congress has already delegated to him, changes in the control of Congress are unlikely on their own to change the administration’s tariff policy. Repealing or constraining those authorities over a presidential veto requires a two-thirds majority in both chambers, and such a majority does not seem to have emerged from this midterm election. So I expect the tariff policy to continue to remain largely under the president’s control, though the future direction of tariffs is subject to legal challenges as well as negotiations with trading partners.

Sam Vigersky is a fellow at CFR. His research and writing focus on humanitarian statecraft and modernizing emergency relief.

The second Trump administration has dissolved the United States Agency for International Development, or USAID, withheld billions in appropriated foreign aid until the money expired, and moved Food for Peace to the U.S. Department of Agriculture. These dizzying moves, among the most consequential foreign assistance decisions in a generation, share a throughline: the White House bypassed Congress. Although Democrats are set to control both chambers, no one should expect the Trump administration to reverse course. Still, the new Congress will juggle three priorities: investigating where the administration overstepped, using aggressive oversight to keep current officials in check, and laying the groundwork for a Democratic return to the White House in 2029 with rising aid budgets and a blueprint for rebuilding foreign assistance. 

Elisa Ewers is senior fellow for Middle East studies at CFR.

Sometimes foreign policy does matter in elections. The Iran war, and its economic consequences for Americans, played a role in the Democrats’ stunning sweep of both the House and Senate. As Democrats prepare to flex Congress’ oversight muscles and demand accountability from the administration, we should expect this to extend to the prosecution of the war. There will be hearings to expose the failed strategy, and legislative efforts to force an end to U.S. military operations and constrain any future wars.  

Congress’ priority of exposing the administration’s corruption could include a scouring of investment deals involving Gulf partners. Then there’s Israel. Democrats will pursue serious limits on military aid and enforce U.S. law, and they may go further—especially if a Netanyahu government and its policies continue. Ideally, Democrats will propose to strengthen diplomacy and support U.S. interests around Iran, Gaza, the West Bank, Lebanon, Syria, and beyond as they look to rebuild the tools of statecraft that the administration gutted. There may be a looming confrontation if Congress imposes holds on administration notifications of spending and uses the appropriations process to put constraints on policy in the Middle East.

On many of these issues, Democrats will need to find even meager support from Republicans since Democratic control over Congress is not veto-proof. Trump may take on an even more adventurist foreign policy, including in the Middle East, as he faces real constraints on his domestic agenda. Congress will need to decide how aggressively it wants to wrestle back its role in decisions of war and peace after decades of ceding ground to the executive.

Liana Fix is senior fellow for Europe and leads the Securing Ukraine’s Future Initiative at CFR.

For European NATO allies and for Ukraine, a Democratic victory in the U.S. midterms does not necessarily mean that their relationship with the United States will improve any time soon. On the contrary: The remaining two years of Trump’s term could be more heavily focused on foreign policy than the first two were. The president may seek to cement his legacy by ending the war in Ukraine—very possibly on terms unfavorable to Ukraine. In the worst case, Europeans fear that NATO and Europe’s security could become part of a deal with Moscow.

A Democratic Congress can pass legislation to constrain the administration, as it has already done by requiring a baseline of 76,000 U.S. troops stationed in Europe. But overriding a presidential veto will require a fair amount of bipartisanship, so Congress alone might not be able to keep relations between Europe, Ukraine, and the United States on a steady trajectory for the next two years.

Joshua Kurlantzick is senior fellow for Southeast Asia and South Asia at CFR.

With Democrats now controlling both chambers of Congress, the United States’ Asian partners and allies will breathe a tiny sigh of relief. Over the past two years, the White House has badly alienated most of its friends in Asia through tariffs and a seeming retreat from security guarantees. The new Congress can use its oversight and investigative powers to shed more light on tariffs, and many Asian business and political leaders also hope that Democrats will be able to rein in Trump’s use of tariffs. That is unlikely, though, given the president’s veto power.

Some Asian leaders also believe Democratic control of Congress could make Republicans more willing to stand up to Trump on other issues important to Asia. As a lame duck, Trump could release some pro–free trade Republican members of Congress to be more willing to defy him, especially if his presence and policies are believed to have hurt these members’ midterm performances. Then again, a lame-duck Trump could also feel even more emboldened to do whatever he wants—a possibility that will make some Asian leaders (and others worldwide) tremble.

Vinh X. Nguyen is senior fellow for artificial intelligence at CFR. He previously served as the National Security Agency’s chief artificial intelligence (AI) officer.

The next Congress will likely aim to codify oversight of lethal autonomous weapons development and use, clarify legal safeguards against using AI to enhance domestic surveillance, and renew the 2015 Cybersecurity Information Sharing Act to bolster threat sharing, if the lame-duck National Defense Authorization Act (NDAA) conference strips them. The new body will also aspire to set rules for powerful AI developers and address job disruption and data center buildout. 

Still, Democrats will need White House buy-in to succeed. This starts with the administration permitting the passage of narrower measures such as disclosing risks and reporting incidents that affect national security and public safety, before turning to a more ambitious legal backstop and institutional design for shared federal and industry safety and security standards. This would include enforcement against developers that fall short.

Michael C. Horowitz is senior fellow for technology and innovation and director of the Defense and National Security Program at CFR.

The midterm elections will increase pressure on the lame-duck session of Congress to pass the NDAA and potentially associated appropriations that fund the president’s top defense priorities. This is not just a question of locking in a higher defense budget than what a Democratic majority might support. Once the new Congress is sworn in, Democrats will likely take shots at specific Trump defense priorities they view as ineffective or wasteful, such as Golden Dome or the Golden Fleet.

The midterms will also lead to a wave of oversight of the Pentagon in 2027, including on perceptions of corruption in contracting, Defense Secretary Pete Hegseth’s controversial firings of senior military officials, the boat strikes off the coast of South America, and Operation Epic Fury in Iran.

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