Did the Iran War Cost Republicans the 2026 Midterms? What the Exit Polls Show

Did the Iran war cost Republicans Congress?

The evidence points to the war as one of the main causes of the Republican defeat, through two channels. It affected votes directly, and it affected them indirectly through the jump in gasoline and diesel prices that followed the closure of the Strait of Hormuz.

This is not only the view of the winning side. President Trump told Fox News that "a part of it was Iran", while adding that people understood the importance of his Iran policy ^[5]. Analysts from both political sides reached similar conclusions. Responsible Statecraft, a publication of the Quincy Institute, headlined its results story "It's the war, stupid" ^[3]. Amber Duke, editor-in-chief of the right-leaning Daily Caller, called the war and its economic consequences "the biggest story of the election" ^[3]. CES Intelligence, a risk consultancy, described the war before the vote as "the single largest identifiable cause" of the administration's electoral deficit ^[14].

The war was not the only factor. In the Associated Press voter survey, about a third of voters called the war a crucial factor, a smaller share than those who named the cost of living or government corruption ^[4]. However, the war was one of the main reasons the cost of living rose, so the two issues are closely linked.

What the exit polls show

The network exit polls show how large the war's effect was. In CNN's poll, 34% of voters said the war was a crucial factor and 40% said it was a major factor ^[1]. NBC's exit poll found that Democrats won 63% of voters for whom the war was a crucial or major factor. Among the 26% for whom it was a minor factor or not a factor, Republicans won 70% ^[2].

The split on the decision to go to war was wider still. In NBC's poll, 63% of voters said military action against Iran was the wrong decision, and 82% of them voted Democratic. Of the 37% who said it was right, 91% voted Republican ^[2]. The AP survey found a similar result, with about six in ten voters calling the use of force wrong ^[4]. CBS found that about a quarter of Republicans agreed, as did voters who were most worried about paying for fuel ^[4].

Voters were also unhappy with the government more broadly. Exit polls found that half of voters saw the election as an opportunity to rebuke the president, and 70% wanted Congress to provide more checks on him ^[5]. Polls before the election showed the same trend. AP-NORC found in October that 62% of registered voters named the war as one of their most important issues. Fox News found that six in ten voters opposed the military action ^[8].

The war and gas prices: two issues or one?

For most households, the war affected their budgets most directly through fuel prices. The Strait of Hormuz, which normally carries about a fifth of the world's oil, closed in March, and gasoline prices reached $4.08 a gallon by early April ^[16]. By late October, Mother Jones put the average at about $4.30 ^[10].

In CNN's exit poll, 87% of voters were concerned about gasoline prices: 59% very concerned and 28% somewhat concerned ^[1]. NBC's poll, as reported by the Daily Caller, found 88% concerned about food prices and 86% about utility bills ^[7]. Ryan O'Donnell of Data for Progress told Responsible Statecraft that foreign policy affects voters "every day", through the extra cost of filling a tank or the higher grocery bills caused by diesel costs ^[3].

Republican leaders had expected the effect to be short-lived. Earlier in the year, House Speaker Mike Johnson called the rise in oil prices a "blip" that would be "very temporary and quick" ^[2]. Instead the war lasted, and peace deals collapsed more than once ^[2].

Where the Republican losses came from

The extent of the Democratic gains in Republican-leaning states suggests a broad shift in opinion. The Associated Press said the Senate majority came through some of the most conservative states in the country ^[6]. Democrats won Senate seats in Kansas for the first time since the 1930s, in Texas for the first time in decades, and in South Carolina, a state Trump won by nearly 18 points in 2024 ^[5]. Ohio and Texas had both voted for Trump by double-digit margins ^[5]. In Florida, Senator Ashley Moody won by only about 3 points in a state Trump carried by 13 ^[5].

Some Republican candidates had already admitted the problem. In leaked audio reported by Axios in October, Ken Paxton, the Republican Senate candidate in Texas, said his campaign's main difficulties came largely from the Iran war and its effect on gasoline prices ^[8]. Republican nominees in Michigan, Maine and Iowa called for a quick end to the war ^[8]. In September, the Washington Post reported that Trump had privately acknowledged that the war was hurting his party's standing ^[17].

Before the vote, Trump also said Republican losses were "possible" ^[9]. In May he had told the Daily Caller that Americans' finances were "not even a little bit" a factor in his Iran decisions ^[7].

The 2006 precedent

Before the vote, many analysts compared 2026 with 2006 ^[8]. In that year, voter dissatisfaction with the Iraq war and with the economy contributed to a Democratic wave. Democrats gained six Senate seats and 31 House seats and took both chambers ^[11].

The two elections have two things in common:

• A war that was expected to be short. In 2003 President Bush declared major combat in Iraq over two months after the invasion ^[11]. The Iran war was described as a limited mission that would be "wrapped up soon" ^[2].
• Costs voters could see. In 2006 the main cost was American casualties. In 2026 it was the price of fuel. The war has cost more than $47.1 billion according to Pentagon estimates ^[4], but the bigger political cost came from higher gasoline prices.

This history is the subject of our analysis of why seven US presidents avoided war with Iran. The domestic political cost of a war in the Gulf has influenced US decisions since 1980.

What the result means for the war

Democrats will control both chambers from January. Al-Monitor reports that House Democrats plan to challenge the administration's claim that it can continue the war without congressional approval ^[12]. In Tehran, parliamentary speaker Mohammad Bagher Ghalibaf described the result as Americans saying "no to war" ^[15]. The president keeps his veto, however, and says he will use it ^[13].

For energy markets, the election has made it more likely that Washington will look for a negotiated end to the war, but it has not reopened Hormuz. We explain what this means for crude, gasoline and freight in our guide to the midterms and oil prices.

Alupetra does not take sides in US politics. This analysis reports what voters, pollsters and the parties themselves have said, because the political outcome affects energy markets and the buyers we work with.