American voters choose a new Congress on Tuesday, and the consequences will ripple across the Middle East, helping determine how freely President Donald Trump can wage war with Iran, arm allies and strike deals.
Republicans currently hold a 218-214 edge in the House of Representatives, with one independent and two vacancies. In the Senate, they hold a 53-47 majority. Those narrow margins mean a handful of races could determine whether Trump faces a Congress controlled by his party in January or an angry opposition party with subpoena power.
The party holding the White House tends to lose seats in midterm elections, and most polls suggest the Democrats are likely to win the House. But the scale of any Republican losses, and whether they can keep the Senate, will determine how much the president’s opponents can constrain his agenda. If Republicans perform more strongly than expected, though, that could instead reinforce Trump’s position for a final two years in office.
Here are three ways the results could affect U.S. policy toward the Middle East:
Funding the Iran War
A Democratic takeover of either the House or Senate could make it harder for Trump to finance the war with Iran — all appropriations bills have to start in the U.S. House of Representatives. That would give Democrats leverage over his requests for funding and more opportunities to grill officials about the war.
Control of either chamber – or both – would also give Democratic lawmakers control of congressional committees, whose leaders could launch hearings to press Trump administration officials to explain their actions.
The sums are substantial. Trump’s $87.6 billion request in June included $21 billion for arms used against Iran and $17.3 billion for operational costs. Sen. Patty Murray of Washington state, the Senate Appropriations Committee’s top Democrat, said in July she opposed “rubberstamping a request to bankroll this war and whatever other misadventures Trump wants to get us into next.”
Trump’s signature regional initiatives could also be subject to closer scrutiny.
The Board of Peace, which oversees Gaza’s reconstruction, offers one potential focus. The Senate Foreign Relations Committee’s top Democrat, Sen. Jeanne Shaheen of New Hampshire, said in June that Congress remained “largely in the dark” about the Board’s work, questioning its legal status and safeguards for donor funds. Senate Democrats reiterated those concerns in a report this week.
Democratic Sens. Ed Markey of Massachusetts and Jeff Merkley of Oregon have also introduced a resolution to block Trump’s civil nuclear agreement with Saudi Arabia, arguing that its safeguards are insufficient to prevent nuclear proliferation.
Support for Israel
A growing number of Democrats are reconsidering the party’s traditional ironclad support for military aid to Israel, and the midterm elections could reflect that shift in Congress.
In a poll published in April by Pew Research Center, about 80% of Democrats and Democratic-leaning independents had an unfavorable opinion of Israel, up from 53% in 2022. In July, AP-NORC found that 58% of Democrats say the U.S. supports Israel too much, up from 45% in January 2024.
Democratic candidates are reflecting those changing views. Senate hopeful Abdul El-Sayed in Michigan supports an arms embargo — including on defensive weapons — on Israel, while challenger Troy Jackson in Maine has pledged to oppose all taxpayer-funded military assistance to Israel. In April, 36 Democratic and Independent senators voted against a $151.8 million weapons sale to Israel, up from 23 the year before.
War and Diplomacy
The scale of any Republican losses on Tuesday could influence how much pressure Trump faces from his own party to change course in the Middle East. If Democrats win in deep red Texas, Kansas and Iowa, along with Alaska and Maine, it would be difficult for Trump to dismiss the losses as a routine midterm setback.
Losses reaching that deep into Republican territory could strengthen arguments that the party needs an exit from the Iran war before the 2028 presidential primaries. That would carry high stakes for Vice President J.D. Vance and Secretary of State Marco Rubio, two potential Trump successors who have staked out vastly different positions on foreign interventions.
It could also lead senators with White House ambitions, like Ted Cruz of Texas and Tom Cotton of Arkansas, to distance themselves from an unpopular policy and an election loss, making the Senate more difficult for Trump when it comes to Iran. In a closely divided chamber, their votes could make a difference.
However, if Republican senators can hold onto their seats in the heartland states of Kansas and Iowa — and even withstand the challenges in Texas, Alaska and Maine — Trump could present the wins as vindication and claim the political capital to pursue more strikes or demand tougher terms from Tehran.
Neither outcome would be a clean referendum, though: polls place the economy and living costs above Iran among voters’ priorities. The question is what lesson Trump and the Republicans hoping to inherit his coalition choose to draw.
