Democrats need a net gain of at least four seats in November’s midterm elections to take control of the United States Senate from Republicans, as voter discontent with President Donald Trump, the Iran war, and rising prices heighten the races in once-safe Republican states.

Republicans currently hold a 53-47 majority, and a Democratic takeover seemed highly unlikely at the start of the year – before the US launched its war on Iran. Here are the key races that could decide the control of the Senate: Alaska Republican Senator Dan Sullivan is seeking re-election against Democratic former US Representative Mary Peltola and an independent candidate who shares Sullivan’s name.

Alaska uses ranked-choice voting, allowing voters to rank candidates in order of preference. Four candidates are on the ballot, including Sullivan, Peltola and another Dan Sullivan a candidate Republicans accuse Democrats of recruiting deliberately to confuse voters.

“It was a scheme. It was election fraud. Total election fraud,” Trump said. Peltola has rejected the accusations, saying the dispute is distracting from voters’ concerns.

“I feel like this is yet another diversion from the issue that Alaskans want to talk about, which is affordability,” she explained.

Peltola has raised $33m in October, compared with nearly $14m for Sullivan. Republicans have also spent more on the race, $42m compared with $38m by Democrats.

Trump won Alaska by 13 points in 2024, but recent opinion polls suggest Peltola narrowly leading over Sullivan.

Iowa has been a Republican stronghold in recent elections, with Trump winning the state by 13 points in 2024. But his declining popularity, trade tariffs and the Iran war have put Republicans on the defence in Iowa.

The state’s agricultural economy has been hit hard by trade tariffs as well as rising fuel and fertiliser costs as a result of the strained oil supplies amid the Iran war.

Republican US Senator Joni Ernst’s decision not to seek re-election has left an open-seat contest between Republican US Representative Ashley Hinson and Democratic state Representative Josh Turek, a two-time Paralympic gold medallist.

Republican Hinson has called for an “immediate end” to the Iran war and said Iowans should not have to pay higher fuel or grocery prices as a result of it. However, according to Politifact Hinson has voted against six resolutions seeking to end US involvement in the Iran war.

Turek has outraised Hinson $20m to $14m, but recent polls show Hinson with a narrow lead.

Iowa Democratic candidate for US Senate Josh Turek in Des Moines, and Iowa Republican Senate candidate, US Representative Ashley Hinson in West Des Moines [AFP] Kansas has not elected a Democrat to the Senate since 1932, but rising farming costs, opposition to Trump’s immigration crackdown and discontent over the Iran war have made this year’s race unexpectedly competitive. Trump won the state by 16 percentage points in 2024.

Republican Senator Roger Marshall is facing Democrat Adam Hamilton, the founding pastor of a Methodist megachurch.

The race has drawn attention from Republican leaders, with both Trump and Vice President JD Vance campaigning in the state.

Agriculture is central to Kansas’s economy, and farmers have struggled with rising diesel and fertiliser prices as a result of the Iran war. Many have also expressed frustration with Trump’s tariffs.

Republican Senator Roger Marshall, right, and Democratic nominee for US Senate Adam Hamilton participate in a debate at WDAF TV in Kansas City [Charlie Riedel/AP] Immigration has become another major issue. Immigration and Customs Enforcement (ICE) raids in southwest Kansas have disrupted businesses. Even Republican Marshall has criticised aspects of the agency’s operations in his state.

Democrat Hamilton has outraised Marshall, $14m to $6m. Democratic groups have also outspent Republicans in Kansas, $28m to $22m. Recent polls show Hamilton narrowly ahead.

is one of the Democrats’ biggest opportunities to gain a Senate seat, as Republican Senator Susan Collins faces a close re-election battle in a state which voted against Donald Trump in 2024.

Collins faces Democrat Troy Jackson, a former Maine Senate president who entered the race in July after the party’s original nominee, Graham Platner, withdrew following sexual assault allegations, which he denied.

Collins has sought to distance herself from Trump, acknowledging during a debate earlier this month that she was not the president’s favourite senator and that he would not be campaigning in Maine.

She was among the Republicans who voted to convict Trump following his impeachment over the January 6, 2021, attack on the US Capitol.

Democrats say Collins only votes against Trump when it doesn’t matter, however. Democrats also hope voters will hold her accountable for helping confirm Brett Kavanaugh to the US Supreme Court, which led to the overturning of a federal right to abortion.

This combination of photos shows Senator Susan Collins, R-Maine, on September 24, 2026, in Washington, left, and her challenger for Maine’s Senate seat, Democratic candidate Troy Jackson on July 16, 2026 [Mariam Zuhaib, Robert F Bukaty/AP] Jackson has faced criticism over his treatment of women, including his refusal to apologise for telling Collins to “shut up” during a debate.

Jackson has outraised Collins, bringing in about $26.9m compared with $25.2m through mid-October. Republican groups have also outspent Democrats, $76m to $40m. Recent polls show a close race.

North Carolina Republicans appear to have conceded where even Trump has suggested the Democrats will win. At a campaign rally last week in Greenville, Trump told supporters it was “crazy” that former Governor Roy Cooper, a Democrat, was going to be their next senator.

Trump won North Carolina by 3 points in 2024, but Republican Senator Thom Tillis’ retirement made this year’s Senate race an open contest.

Trump recruited former Republican National Committee Chairman Michael Whatley to succeed Tillis, but he has been unable to compete with Cooper’s fundraising, and Republican allies who invested heavily in holding North Carolina have begun shifting their focus to other states.

Affordability has dominated the campaign as farmers struggle with rising diesel and energy costs amid the Iran war.

In eastern North Carolina, Kelly Spivey, who runs a community food pantry, told Al Jazeera that rising prices are forcing families to make difficult choices.

“They’re trying to decide if they’re going to pay for their medicine or they’re going to buy food or they’re going to pay for day care so they can actually go to work,” she said.

Whatley, meanwhile, has closely aligned himself with Trump, who told supporters at a campaign rally: “I just want you to go out and pretend I’m on the ticket because essentially I am.”Cooper has raised $50m and has $9m in the bank. Whatley has raised $14m and has just $900,000 on hand through mid-October. Recent polls have Cooper leading by double digits.

At left, Michael Whatley speaks June 18, 2024, in Newtown, and at right, North Carolina Governor Roy Cooper, on October 5, 2024, in Charlotte [AP] Ohio Democrat Sherrod Brown, who has longstanding ties to labour unions and working-class communities, is seeking to win back voters in the industrial Rust Belt state.

Brown faces US Senator Jon Husted, who was appointed to the Senate to replace US Vice President JD Vance when Vance left the Senate for the White House. The cost of living has become a major campaign issue.

This combination of pictures created on October 30, 2026 shows (L/R) Ohio Democratic candidate for US Senate Sherrod Brown in Warren, Ohio, on September 26, 2026 and US Senator Jon Husted, Republican from Ohio, in Cincinnati, Ohio, on October 24, 2026 [AFP] The winner of the special election will be on the ballot again in 2028 for a full six-year term.

Republican and Democratic outside groups have each spent nine figures on the race, with Republicans investing $232m and Democrats pouring in $118m.

Brown has more than tripled Husted’s fundraising through October 14, bringing in $68m to Husted’s nearly $20m. Recent polls show Brown leading by three to five points.

Texas No Democrat has won statewide in Texas since 1994. James Talarico, a state representative, could break the streak. Talarico faces Republican Attorney General Ken Paxton.

Trump won Texas by nearly 14 points in 2024. Yet Republican outside groups have already spent $300m to hold the seat after run-off voters nominated the scandal-plagued Paxton over incumbent Republican US Senator John Cornyn.

Trump endorsed Paxton even though Cornyn was widely believed to have an easier path to victory.

Leaked audio has exposed daylight between Trump and Paxton, who privately told donors that the president’s midterm convention hurt his campaign.

Democratic groups have spent $76m on this race. But Talarico’s campaign has outraised Paxton’s by $110m and reported $9.6m more in its campaign coffers as of September 30.

Musk has given $158m to a Republican super PAC to invest in Paxton’s race. Recent polls show Talarico narrowly leading or tied.

Georgia was initially seen as one of the Republicans’ main opportunities to gain a Senate seat after Trump won the state by 2 percentage points in 2024. But Republican US Representative Mike Collins has struggled to gain traction against Democratic US Senator Jon Ossoff, a potential 2028 presidential candidate.

Ossoff has outraised Collins by nearly $126m up to October 14 and began mid-October with $15.1m in his war chest, compared with Collins’ $1.1m.

Polls have consistently shown Ossoff leading, and Democrats narrowly lead Republicans in outside spending, $19m to $17.9m.

This combination of pictures created on October 30, 2026 shows (L/R) US Senator Jon Ossoff, Democrat from Georgia, in Atlanta, Georgia, on October 13, 2026 [AFP] Michigan Republicans are more hopeful about flipping an open seat in Michigan especially after the Democratic establishment failed to get its pick nominated.

Progressive outsider Abdul El-Sayed narrowly defeated centrist US Representative Haley Stevens during the primary, putting him on a collision course with Republican Mike Rogers, a former US representative, in what could be the tightest race for a Democratic-held Senate seat this year.

Michigan, a key battleground state which Trump won in 2024, has been hit by tariffs affecting trade with neighbouring Canada and rising living costs, making the economy a central issue in the campaign.

The race has also attracted heavy spending from outside groups. A pro-Israel super PAC has spent at least $493,000 opposing El-Sayed, after spending $30m in an unsuccessful effort to prevent him from winning the Democratic nomination. The group could spend as much as $9m more during the general election.

El-Sayed raised $45m up to September, more than double Rogers’s nearly $21m.

Republican groups have spent $136m on the race, compared with about $70m by Democrats. Most recent polls show El-Sayed narrowly ahead.

New Hampshire Democrats are defending an open Senate seat in after Senator Jeanne Shaheen announced her retirement, giving Republicans an opportunity to compete in a state Kamala Harris won by nearly three percentage points in 2024.

Democratic US Representative Chris Pappas faces former Republican Senator John Sununu, who is seeking a return to Washington nearly two decades after losing his seat to Shaheen in 2008.

Sununu comes from one of New Hampshire’s best-known political families. His brother, Chris Sununu, served as governor until 2025.

Pappas has a substantial fundraising advantage, raising $24m compared with Sununu’s $6m.

Republican outside groups have also outspent Democrats, $37m to $20m, as both parties compete for the open seat. Recent polls have consistently shown Pappas leading Sununu by five to eight percentage points.