2026 US Midterms: Six Factors That Could Decide Congress

The 2026 US midterm elections are taking place on November 3, with voters deciding the balance of power in Congress and thousands of state and local offices. All 435 seats in the House of Representatives, 35 Senate seats and 36 governorships are being contested, making the election a major test of President Donald Trump‘s second-term agenda.

More than 54 million Americans had already cast their ballots by Monday, according to the University of Florida Election Lab tracker. The scale of early voting reflects the high level of political engagement surrounding an election that could reshape the legislative landscape for the remainder of Trump’s presidency.

Democrats are seeking to regain control of Congress, while Republicans are attempting to retain their majorities through their existing electoral support and newly redrawn congressional boundaries. The outcome will depend on several interconnected factors, including Trump’s approval ratings, economic pressures, the impact of the Iran war, redistricting disputes, competitive Senate races and voter turnout.

Election administration and legal challenges have also become important parts of the campaign. Together, these six factors will shape the contest for congressional control and determine how much influence each party has over national policy and government oversight.

1. Trump’s Popularity and the Referendum on His Presidency

President Donald Trump’s approval ratings are among the central factors influencing the 2026 midterm elections. Although Trump is not personally contesting a seat, his second-term record has become a major issue in congressional campaigns, with voters assessing his administration’s decisions and performance.

Midterm elections often become a public assessment of the sitting president’s administration. The party controlling the White House faces the challenge of defending its record, while the opposition attempts to connect congressional candidates to voters’ concerns about national leadership and government policy.

Recent polling has indicated substantial dissatisfaction with Trump’s performance. A Reuters/Ipsos poll published on October 19 placed his approval rating at 31%, the lowest reading of either of his presidential terms. A separate Washington Post-ABC News-Ipsos survey recorded 33% approval and 66% disapproval.

These figures provide an indication of the political environment surrounding Republican candidates. However, presidential approval ratings do not automatically translate into congressional results. Individual races are also influenced by local issues, candidate profiles, party organisation and the political preferences of voters in each district or state.

A CBS News/YouGov poll conducted between October 21 and 23 described the election as an “avoidance” contest, with voters motivated by opposition to the other party. More than seven in 10 respondents supporting Democrats said their congressional vote was intended to oppose Trump.

This suggests that opposition to the president has become an important motivation among Democratic voters. At the same time, Republicans are relying on their own supporters to defend congressional seats and maintain the party’s influence in Washington.

Trump has responded with an extensive campaign effort, holding rallies and tele-rallies across several states. Former president Barack Obama has also campaigned for Democratic candidates, including Charles Booker in Kentucky and Troy Jackson in Maine.

The involvement of prominent national political figures highlights the importance both parties attach to the midterms. The extent to which Trump’s approval ratings influence individual congressional contests will become clearer through the results across competitive districts and states.

2. Cost of Living, Fuel Prices and the Iran War

Economic concerns, particularly the cost of living, are another major factor shaping voter sentiment ahead of the midterm elections. Household expenses, fuel prices and the cost of essential goods have become important campaign issues as Americans assess the economic consequences of government decisions.

The US war with Iran, launched alongside Israeli strikes on February 28, disrupted shipping through the Strait of Hormuz. Before the conflict, the strategic waterway carried roughly one-fifth of global oil supplies, making it an important route for international energy markets.

Although a ceasefire took effect in April, tensions and intermittent clashes have continued. The disruption and uncertainty surrounding the conflict have contributed to concerns about energy supplies and the cost of fuel.

US petrol prices increased from just under $3 per gallon to more than $4 after the conflict began, according to AAA data. Higher fuel costs can affect household budgets directly, while also increasing transportation and operating expenses for businesses.

The economic consequences have become a political issue for the Trump administration. A Chicago Council on Global Affairs survey found that 86% of Americans believed the war had hurt the cost of living, while 68% said it was not worth fighting.

An AP-NORC survey also found that 65% of US adults attributed higher-than-usual prices to Trump’s policies. By comparison, 44% blamed Joe Biden’s policies for higher-than-usual prices in October 2022.

These findings indicate how economic conditions and foreign policy can become connected in voters’ assessments of the government. While international conflicts may have consequences beyond the control of any single administration, voters can still judge the decisions made by political leaders and their perceived impact on everyday expenses.

The pressure has also reached agricultural communities. Higher diesel and fertiliser costs have added to existing difficulties involving drought, lower commodity prices and trade disputes. These concerns have become relevant in states where farming and related industries play an important role in the local economy.

The Kansas Senate race is among the contests where agricultural and economic concerns have contributed to a more competitive political environment. For candidates in rural areas, the cost of fuel, fertiliser and other essential inputs can become significant campaign issues.

The wider economic debate is therefore likely to influence how voters assess both parties. Democrats can point to rising household expenses as an issue requiring greater political accountability, while Republicans must defend the administration’s economic record and explain its approach to energy and international affairs.

3. Redistricting Battles and the Supreme Court

Changes to congressional boundaries have added another important dimension to the 2026 midterm elections. An aggressive round of mid-decade redistricting has altered the electoral map in several states, affecting the political calculations of both parties.

The latest redistricting battle began in 2025, when Trump urged Texas Republicans to redraw the state’s congressional boundaries. The proposed changes were intended to create up to five additional Republican-leaning seats in the House of Representatives.

Other Republican-led states, including Missouri, North Carolina and Ohio, subsequently adopted new congressional maps. These changes formed part of a broader effort to adjust district boundaries ahead of the midterm elections.

Democrats responded with their own redistricting effort in California. Voters approved Proposition 50 in November 2025, introducing a new congressional map designed to offset Republican gains in Texas.

The competing changes demonstrate how congressional boundaries can influence the political environment before voters cast their ballots. A redrawn district can change the composition of its electorate and affect the type of candidates and campaigns that parties prioritise.

The Supreme Court also played a role in the evolving redistricting debate. Its April 29 ruling in Louisiana v. Callais altered the legal landscape surrounding congressional maps and the use of race in redistricting challenges.

The 6-3 decision limited the use of race-based challenges to congressional maps under Section 2 of the Voting Rights Act. The ruling has implications for how states and courts assess claims involving electoral boundaries and minority representation.

Florida, Tennessee, Alabama and Louisiana also made changes to their congressional boundaries. As a result, the electoral calculations in several states have been affected by a combination of new maps, legal disputes and competing political strategies.

Redistricting does not determine the outcome of an election by itself. Voters still decide who represents their districts, and candidates must compete within the boundaries established for their constituencies. However, changes to district maps can influence the number of competitive seats available to each party.

For Democrats, the challenge is to overcome Republican advantages in some newly drawn districts while defending seats in states where the boundaries have changed. Republicans, meanwhile, are seeking to benefit from maps that could improve their position in the House.

4. The Battle for the Senate

The Senate elections present a separate challenge for both parties. Republicans currently hold a 53-47 majority, meaning Democrats need a net gain of four seats to take control of the chamber.

Thirty-five Senate seats are being contested, including special elections in Ohio and Florida. Several races have attracted attention because of their competitive ratings and potential influence on the balance of power.

According to CBS News ratings, Maine, Michigan, Ohio, Texas and Alaska are classified as toss-up contests. Iowa, Kansas and South Carolina lean Republican, while Georgia, North Carolina and New Hampshire lean Democratic.

These classifications reflect the competitive nature of individual races rather than guaranteed outcomes. Senate contests can be influenced by state-level political conditions, candidate backgrounds, campaign spending, voter participation and national political developments.

Decision Desk HQ’s model, as of Monday, put Democrats’ chances of winning the Senate at 64%, with a projected 52 seats. The Cook Political Report identified seven toss-up contests: Alaska, Iowa, Kansas, Maine, Michigan, Ohio and Texas.

The number of competitive races makes the Senate contest particularly important. Democrats need to win multiple closely contested states while protecting seats in states where Republican candidates are competitive.

Republicans, on the other hand, are defending their existing majority. Their ability to retain seats in competitive states will determine whether they continue to control the chamber or face a change in the Senate’s political balance.

Control of the Senate has consequences beyond the passage of legislation. The chamber plays an important role in confirming presidential appointments and considering other major government decisions. A change in its majority could therefore affect the administration’s ability to advance its priorities.

The House and Senate contests must also be considered separately. A party can gain control of one chamber without winning the other, creating the possibility of divided control of Congress.

5. Early Voting and the Turnout Factor

Voter turnout is another major factor that could influence the 2026 midterm elections. More than 54 million Americans had already voted before Election Day, according to the University of Florida Election Lab tracker.

The number of early ballots increased from approximately 45 million on Thursday to nearly 50 million on Friday before crossing the 54 million mark by Monday. These figures highlight the scale of participation before November 3.

Democratic participation has been strong in several states. The CBS News poll also found that more Democratic supporters said they had already voted or were certain to vote.

However, early voting figures alone cannot establish which party will win. Early ballots do not necessarily represent the final distribution of votes, and the political preferences of people who vote before Election Day can differ from those who turn out on November 3.

Republicans have traditionally performed better among Election Day voters. The same CBS survey found that voters who were only considering voting leaned Republican.

This creates a challenge for both parties. Democrats must ensure that strong early participation translates into sufficient support across all voting methods, while Republicans need to mobilise their supporters who plan to vote on Election Day.

Turnout can vary significantly between states and congressional districts. Local campaign organisations, candidate outreach, voting rules and the level of public interest in particular races can all affect participation.

The number of ballots cast is therefore only one part of the picture. The geographic distribution of those votes and the participation levels of different voter groups will also matter when results are counted.

For candidates competing in close races, even relatively small differences in turnout can affect the final margin. The balance between early voting and Election Day participation will be an important part of understanding the results.

6. Election Security, Federal Monitoring and Legal Challenges

Election administration and security have become another area of political and legal dispute ahead of the midterms. The involvement of federal agencies, access to polling locations and challenges involving mail ballots have raised questions about the responsibilities of state and federal authorities.

The Justice Department has announced plans to deploy more than 1,000 federal monitors at polling locations across all 50 states. This represents a substantial increase compared with the 388 monitors deployed during the 2022 midterm elections.

However, the monitoring plans have faced restrictions in some states. Minnesota and Wyoming are among those that have limited Justice Department monitors’ ability to access polling locations directly.

California has emerged as a major legal battleground over election administration. The Justice Department alleged that approximately 20,000 people who received mail ballots might not be citizens and sought an order requiring the state to set those ballots aside.

California officials disputed the reliability of the list. A federal judge rejected the Justice Department’s request, and a 2-1 panel of the 9th US Circuit Court of Appeals declined to overturn that decision.

Separate legal proceedings have also resulted in restrictions on actions by the administration involving California election officials and ballot counting.

These disputes highlight the legal boundaries surrounding election administration in the United States. The country’s electoral system is administered primarily by state and local authorities rather than directly by the White House.

Courts remain an important check on federal intervention, particularly when disputes arise over election procedures, voter eligibility and the counting of ballots. Election law experts have also emphasised that the president has no emergency power to take direct control of elections.

For voters and candidates, the central issue is whether elections are conducted under established legal procedures and whether disputes are resolved through the appropriate institutions. Legal challenges can influence the administration of particular contests, but they do not automatically determine the broader national result.

What the 2026 Midterm Elections Could Mean for Trump’s Presidency

The 2026 midterm elections will determine the balance of power in Congress during the remainder of Trump’s second term. A change in control of either chamber would affect the administration’s ability to advance legislation and could reshape the relationship between the White House and congressional leaders.

If Democrats regain control of the House or Senate, they would gain greater authority over legislative priorities and congressional oversight. Control of a chamber would also give the party a stronger position in negotiations over government spending, policy proposals and investigations.

If Republicans retain their majorities, the administration would continue to work with a Congress controlled by its own party. That could provide greater continuity for Trump’s legislative agenda, although the outcome of individual races and the size of the majorities would still matter.

The election could also produce divided control, with Republicans retaining one chamber while Democrats gain the other. Such an outcome would create a different political environment, requiring greater negotiation between the parties on legislation and government oversight.

Ultimately, the result will not depend on a single national issue. Trump’s approval ratings, household costs, the Iran war, redistricting decisions, Senate contests, turnout and election administration will all contribute to the political landscape on November 3.

The distribution of votes across individual congressional districts and states will determine whether Democrats can regain control of Congress or Republicans can retain their majorities. The outcome will shape the legislative and oversight authority available to both parties for the rest of Trump’s presidency.