US election: Ten key races in the battle to control the Senate

Congressional race will be key on Tuesday, with Democrats needing up to four extra Senate seats

The eyes of the world will turn to the US this week as one of the most consequential presidential elections in history takes place, yet the race to the White House is not the only issue on the ballot.

Millions of Americans will cast their votes in congressional and state elections. All 435 seats in the House of Representatives are up for grabs, and 33 of the Senate’s 100 seats will be decided.

The make-up of the next Congress will shape the political direction of the country from January. If Joe Biden wins the election he will be constrained in his ability to advance his policy priorities if Democrats are not in control of the House and Senate.

While Democrats are expected to retain their House majority, the Senate is a more difficult prospect. Republicans control 53 seats, with the result that Democrats need to win four additional seats for a majority, or three if Biden is elected as vice-president Kamala Harris would cast any tie-breaking votes. In reality a larger majority is desirable to ensure the party holding it has enough wriggle-room to pass legislation.


Up to a dozen Senate seats are in flux in this week's election, though realistically Democrats are perceived to have a fighting chance of flipping up to four currently held by Republicans. Additionally, Republicans are expected to win back the Alabama seat that Democrat Doug Jones won in a special election in 2017.

Jones ran against a historically-poor candidate in Roy Moore, who faced multiple accusations of sexual assault, and the deeply red state of Alabama is expected to swing back behind the new Republican candidate this time around.

Here are 10 states Democrats are hoping to gain in Tuesday’s senate contest.


This state is seen as the Democrats' best pick-up opportunity. Former astronaut Mark Kelly, the husband of former congresswoman Gaby Giffords who survived a shooting to the head in 2010, is leading his Republican rival – incumbent Martha McSally – by an average of approximately 3.5 per cent.

McSally was appointed to fill the late John McCain's seat. She had contested the Arizona Senate contest in 2018 but narrowly lost to Democrat Kyrsten Sinema, before she was appointed to the Senate after McCain's death.

McSally has come under pressure from constituents over her support for Donald Trump. A strong defender of the president on Capitol Hill, she repeatedly refused to answer during a recent debate with Kelly as to whether she was proud of her support for Trump. "I'm proud to be fighting for Arizona every single day," was her response as she repeatedly dodged the question.

It appears that the president took note. At a campaign event in Arizona last week, Trump hurried McSally on to the stage, telling her to keep her comments short. “One minute, Martha – they don’t want to hear this,” he said as she joined him on stage.

Should Kelly win Arizona will have two Democratic senators for the first time – a measure of the political changes taking place in this once reliably-Republican state.

South Carolina

Republican senator Lindsey Graham faces an unexpectedly strong challenge from Jaime Harrison. The 44-year-old African-American Democrat has attracted a record-breaking amount of donations, raising $57 million (€49m) in the third quarter.

Graham, a staunch ally and golfing buddy of Trump's who has moved further to the right in recent years, is seeking re-election for a fourth term. He is hoping that the recent confirmation of supreme court justice Amy Coney Barrett will help highlight the work he has done in helping shepherd through conservative judges and justices through the Senate in recent years.

While there are indications of voter fatigue with Graham in his home state, South Carolina is still reliably Republican. Polls show that Graham is leading his Democratic opponent, who has been boosted by high-profile endorsements by figures such as Barack Obama. Nonetheless, the Real Clear Politics polling data aggregator still has the race a toss-up, so it will be closely watched on election night.


Senator Susan Collins is in the fight of her political life as she tries to defend her seat in Maine, America's most northeasterly state. She faces a challenge from Sara Gideon, currently the speaker of the state's House of Representatives.

Collins, who has represented Maine since 1997, has grappled with her support for Trump during his presidency given that he is not particularly popular in her home state.

At several key moments over the last four years she has broken with her party. She was the only Republican to vote against Barrett’s nomination to the supreme court last week. However, during the impeachment process earlier this year she ultimately voted to acquit the president, disappointing liberals.

Virtually every poll in recent months has Gideon ahead. Maine's unique voting system may also aid Democrats. The state operates a ranked-choice system, much like the single-transferable voting system in Ireland. The Democratic candidate is likely to be the second choice for voters who put a third-party candidate as their first choice. Independent candidate Lisa Savage is running a relatively high-profile campaign in the state.

North Carolina

Democrats see an opening in the swing state of North Carolina, where Republican incumbent Thom Tillis faces a challenge from Democrat Cal Cunningham. The race took a remarkable twist last month when both candidates became embroiled in controversy.

Tillis was one of two Republican senators who tested positive for coronavirus following Barrett's nomination ceremony at the White House on September 26th. The same week text messages between Cunningham and a woman who is not his wife emerged, and he admitted an affair. The Iraq war veteran and father of two has refused to comment on the controversy since his first statement expressing regret. Nonetheless, Republican ads are hammering the Democratic candidate on local airwaves, questioning his character and integrity.

However, the latest polls show that the revelations have had little impact on the race. While an NBC-Marist poll last week had Cunningham 10 points ahead, his lead is closer to 3 points on average, with Real Clear Politics characterising the contest as a toss-up.


While Trump won Montana by a comfortable 20 points in 2016, the Big Sky state has always had an independent streak. Many of its state governors have been Democrats, including Steve Bullock, who ran for the Democratic nomination for president last year.

A year later he is now competing for one of the state's two Senate seats. Republican Steve Daines has held the seat since 2014 and is a strong supporter of Trump. In a state boasting acres of natural beauty, Daines has been touting his achievements as a "conservative conservationist" representing Montana in Washington, highlighting in particular his role in agreeing the Great American Outdoors Act, a landmark piece of environmental legislation.

As with many Democratic challengers this election cycle, Bullock has outraised Daines in terms of fundraising. However, it is unclear if Bullock, though popular, will have enough support in the sparsely-populated state to get him over the line. An average of polls in October put Daines just one point ahead of Bullock.


Interest in Iowa usually peaks around early February when it holds the first-in-the-nation caucuses, but this year the mid-western state has risen to national prominence as election day nears. Polls show both the presidential and Senate races tightening here, with Trump and Biden visiting in recent days.

In the Senate race Republican Joni Ernst faces a strong challenge from Democratic candidate Theresa Greenfield. Ernst, who won her first term in 2014, memorably declared in a campaign ad: "I grew up castrating hogs on an Iowa farm, so when I get to Washington I'll know how to cut pork ... Let's make 'em squeal."

Now she is feeling the heat as Democratic money pours in for her challenger Greenfield. In addition, her unwavering support for Trump during her time in the Senate may be problematic as polls show that the president’s standing is slipping in the state.

Greenfield is a political newcomer with a background in real estate. Yet so far she is slightly ahead in the polls. The Real Clear Politics poll average puts her 1.5 percentage points ahead of the Republican incumbent. A poll by the respected Des Moines Register on Saturday night ahead of Trump’s visit on Sunday put Ernst four points ahead, with Trump leading Biden by seven points.


The southern state is shaping up to be one of the most interesting to watch on election day. Both Trump and Biden are campaigning there in the final two days as Trump seeks to defend a state he won easily in 2016.

But Georgia’s two Senate races are also attracting national scrutiny. In an electoral quirk, however, candidates need to pass a 50 per cent threshold to win, with the result that run-off races are possible in both contests.

Democrats are most confident about the prospects for Jon Ossoff – he competed in a special congressional election in 2017, only narrowly missing a seat to the Republican candidate, and is now back on the ballot for the Senate. His opponent David Perdue pulled out of the final debate between the two candidates scheduled for Sunday.

Democrats are hoping that increased voter turnout in Georgia and the changing demographics of the state could push him over the 50 per cent needed.

The other race is less likely to have a definite winner because two Republicans are competing, and may split the vote. Incumbent Kelly Loeffler and Republican Doug Collins, who is running further to her right, are competing with Democratic candidate Raphael Warnock and several others on the ballot.


Democrats are hopeful of picking up a seat in the Rocky Mountain state. Republican incumbent Cory Gardner was first elected in 2014, and defeated a Democratic incumbent narrowly that year. Now he is facing a strong challenge from John Hickenlooper.

The former governor and candidate for the Democratic nomination for president, Hickenlooper is well-known and well-liked in the state. He has also amassed a considerable election war chest, like many Democratic candidates across the country. But the real reason he may unseat Gardner is Trump.

Trump’s relative unpopularity in a state that has already shifted leftwards from 2014 is boosting Hickenlooper’s chances, according to polls. Like many Republican senators, Gardner has been caught between pleasing Republican voters who have remained loyal to Trump over the past four years, and trying to appeal to independent voters.

While relatively few polls have been conducted, the most recent YouGov/University of Colorado poll put Hickenlooper 9.5 percentage points ahead.


John Corbyn, the incumbent Republican, looks likely to retain his seat here, but the race has been surprisingly competitive. Democrat candidate MJ Hegar, a 44-year-old former air force pilot, is challenging Cornyn (68), who is seeking a fourth term.

The last time Texas elected a Democratic senator was in 1988, and El Paso-native Beto O'Rourke came close in 2018 when he ran a well-funded campaign to unseat Ted Cruz. But the enthusiasm around his candidacy was not enough to flip the seat.

The big change this time around has been turnout. More than 9 million Texans had already voted by this weekend, surpassing the total number of votes cast in 2016. Huge voting numbers in Harris County, which encompasses Houston, has boosted Democratic hopes that 2020 could see a seismic shift away from the Republican party in the Lone Star state.

A strong performance by Biden in Texas could bring Senate candidate Hegar along with him. Hegar has also benefitted from an influx of cash, outraising Cornyn by three to one in the first two weeks of October. Nonetheless, polls show she lags Cornyn. The Real Clear Politics average of polls has him 7.5 percentage points ahead.


It may be a long shot but Democrats hope the seat could help tip control of the Senate their way. Republican incumbent Dan Sullivan is facing a challenge from Al Gross. Technically Gross is running as an independent, but if elected he would caucus with Democrats in the Senate in a similar way to how Bernie Sanders votes with Democrats despite being an independent.

Gross, an orthopaedic surgeon and former fisherman, positions himself as a moderate, underlining his commitment, for example, to preserving the second amendment right to bear arms.

Though Alaska is America's biggest state by landmass it has a population of just 700,000. However, money is pouring into this race, including from high-profile organisations like the Lincoln Project, an anti-Trump Republican group

Polling is notoriously difficult in Alaska, which makes it particularly difficult to gauge politically. It is also likely to be some time before a final result emerges from the northwestern state. It will be the last state to begin counting absentee ballots, and a definitive result is not expected until at least a week after election day.