It’s a contest that will set the direction of the United States for the next two years, affecting everything from abortion rights to the Capitol riot investigations. Its outcome could make Joe Biden’s life a lot more difficult. And it will be a factor in whether Donald Trump runs for the White House again.

Yes, it’s another midterm election in America.

The midterms are known for their unpredictability and this one isn’t short of quirks: more than one celebrity has thrown their hat into the ring and dozens and dozens of deniers of the 2020 presidential election result are running for the Republicans, most of them endorsed by Trump as he lays groundwork for a run in 2024. “We’ve never had a former president insist on being ‘on stage’ for his successor’s midterm election,” says political analyst Larry Sabato, director of the Centre for Politics at the University of Virginia. “It really is unprecedented.”

As the campaign enters its final sprint, concerns about the economy, crime, immigration and even Biden’s age have placed his party at risk of losing its narrow congressional majority.

What are the midterms? What are the key issues and contests to watch? And how likely is it that the tables will turn in Washington?

What are the US midterms?

Midterm elections take place two years into a presidential four-year term. While Biden isn’t up for re-election until 2024, midterms are a clear barometer of the national mood and almost always a referendum on the incumbent administration.

All 435 seats in the House of Representatives are up for grabs, along with 35 of the 100 seats in the Senate (senators serve six-year terms, so their elections are staggered). Laws pass through the House and must be approved in the Senate. Both bodies together are Congress, control of which is the name of the game.

Below is a graphic showing the current state of play. Things aren’t looking great for Biden and the Democrats. Boiled down, the Republicans would need to flip just five Democratic seats to gain a majority in the House.

In the Senate, as illustrated below, the Democrats have 50 seats – as do Republicans – and hold the majority only by virtue of the Vice-President (Kamala Harris) having a tie-breaking vote. The Republicans would need just one extra seat to win control.

But there’s more. Many states have timed their elections to this federal schedule, so 36 state governorships are also being contested. Governors are the equivalent of Australia’s state premiers; they have immense power over a swathe of issues from women’s reproductive rights to gun laws to the way race and diversity can be taught in schools.

Other state and local positions will also be contested, including that of secretary of state, the chief elections official for a jurisdiction (more on that below).

“The choice couldn’t be clearer – and the stakes couldn’t be higher.”

People will be asked to vote on numerous state-based measures, too. Residents in Vermont, California and Michigan will vote on whether to amend their state constitutions to establish some form of a right to abortion. In five other states, including South Dakota and Arkansas, voters will decide on whether to decriminalise recreational marijuana use.

“I can’t think of a more consequential election that I’ve been involved in,” Biden has said. “The choice couldn’t be clearer – and the stakes couldn’t be higher.”

Well, what’s at stake?

Put simply, the direction of the country for the next two years. Biden has achieved a considerable amount so far, such as a bipartisan infrastructure bill, historic climate change reforms and basic gun control. But he has also struggled to do other things, such as reforming voting rights or codifying abortion protections into federal law, because Democrats don’t have enough votes in the Senate.

If Republicans end up winning control of both the House and the Senate, this will make it even harder for the president to deliver on his policies. Importantly for Australia, the US posture on China, trade agreements and defence support can also depend on who has the majority.

“The simple fact is, the party that controls each chamber sets the agenda,” says Gary Nordlinger, a politics professor at George Washington University. “If Biden could at least keep the Senate, he can get judges confirmed and treaties ratified, but if he has no chambers in Congress, he loses the ability to set any agenda and he becomes reactive to them instead of a leader of them.”

Republicans have made it clear that if they take back Congress, they would gut the work of the committee looking into the January 6 Capitol attack and launch their own inquiries, including, potentially, into the alleged financial improprieties of Hunter Biden, the President’s son, and the alleged “weaponisation” of the Justice Department that resulted in the raid on Trump’s Mar-a-Lago home.

Of a total 552 Republican nominees running for office, 199 fully denied the outcome of the 2020 election.

According to the Republican Party’s legislative blueprint, there would also likely be support for further tax cuts and less government spending, and greater emphasis on culture wars, such as support for laws seeking to ban trans women from playing on women’s sports teams. As for abortion, Senator Lindsey Graham has already introduced a bill that would ban it after 15 weeks of pregnancy (with exceptions for cases involving rape, incest or risks to the life and health of the mother). “If we take back the House and Senate, I can assure you we’ll have a vote on the bill,” Graham said in September.

Then there’s the matter of the health of US democracy. Dozens of Republicans who have endorsed Trump’s views of electoral fraud are seeking a seat in Congress or are seeking to be elected state governor or secretary of their home state, two crucial roles that vest the power to set electoral rules and even determine whether to accept or deny the results of an election under the US’s highly decentralised voting system.

Of the 552 Republican nominees running for office, 199 fully denied the outcome of the 2020 election by either stating publicly that it was stolen or by acting to overturn the results, found one analysis by political news site FiveThirtyEight.

If just some of these candidates get into office, the consequences could be startling. An election-denying secretary of state could refuse to certify the results of an election that she or he believes is “stolen” or “rigged”. A governor could submit electoral votes that defy the will of the people. And without rigorous safeguards, a Congress stacked with election deniers could help Trump – or any other fellow election denier – to overturn a future presidential election if they didn’t like the result.

What’s the likely outcome?

The conventional wisdom is that the Republicans are likely to win back control of the House but the Senate will come down to a handful of seats, including in Pennsylvania, Georgia and Nevada.

History is not on the President’s side. Whoever holds the White House generally suffers congressional losses two years later. Think of the “thumping” George W. Bush’s Republicans suffered in 2006; the “shellacking” of Barack Obama’s Democrats in 2010; and the blue wave against Donald Trump’s Republicans in 2018.

What’s more, Biden’s approval rating remains dismally low amid sweeping dissatisfaction over cost-of-living pressures, crime and immigration, all of which are central to the Republicans’ campaign pitch.

As of October 25, the latest RealClearPolitics average, which aggregates public polling, has Biden with an approval rating of 42.6 per cent. This is slightly lower than Trump’s rating in October 2018, when the Democrats picked up 40 House seats in the midterms, and almost five points lower than Obama’s approval rating in 2010 when he lost 63 seats to Republicans.

Yet the big driver of public opinion is inflation, which has soared to 40-year highs in America. On this measure, Republicans have the edge, as more Americans trust them to address economic issues than they trust Democrats, according to a new ABC/Ipsos poll.

“While this election has not turned out to be a straight-up referendum on Biden’s stewardship over the economy, it still was a strong factor and one that provided a gravitational pull that is hurting his party’s chances greatly,” says election analyst Charlie Cook, founder of the non-partisan newsletter The Cook Report.

Cook says if Democrats “come even close to maintaining one or both majorities, they should have three factors to be grateful for”. Firstly, abortion for motivating the party and diverting some attention from the economy. Secondly, Donald Trump for “being and behaving like Donald Trump”. And thirdly, the Republican primary voters “who turned down quite a few pretty electable contenders in favour of far more problematic candidates”. One controversial candidate is Herschel Walker in Georgia, a former NFL star whose campaign has been plagued with gaffes as well as domestic violence allegations and, more recently, claims of hypocrisy over abortion, which he denies.

What are the key contests to watch?

Herschel Walker, a former football player backed by Trump, is trying to unseat Democrat Raphael Warnock, Georgia’s first black senator.

Georgia is home to two of the most critical contests of this year’s midterms. The first could shift the balance of power in the Senate: Trump-backed Herschel Walker (above right) is trying to unseat Democrat freshman Raphael Warnock (left), Georgia’s first black senator and a pastor at the Ebenezer Baptist Church. The second is the governor’s contest between Republican incumbent Brian Kemp, who pushed back against Trump’s attempt to overturn the 2020 presidential election result, and voting rights activist Stacey Abrams, whose effort to mobilise black voters in Georgia is widely credited with Biden’s victory. Once a Republican stronghold, Georgia is younger and more diverse and progressive than it was, making it highly competitive and largely dependent on black and brown communities showing up to vote (voting is not compulsory in the US).

In Pennsylvania, TV’s Dr Oz is up against tattooed progressive John Fetterman.

In its battle between Trump-backed TV doctor Mehmet Oz (above left) and tattooed progressive John Fetterman (right), Pennsylvania is regarded as the Democrats’ best chance of flipping a seat in the Senate, even while a stroke suffered by Fetterman earlier this year has upped scrutiny of his health and fitness for the job. Retiring Senator Pat Toomey is one of the few Republicans who voted to impeach Trump. Pennsylvania is also the ultimate swing state. Democrats held it for 24 years until Trump won it against Hillary Clinton in 2016. In 2020 it narrowly swung back to Biden but, in a last-ditch effort to stave off defeat, Trump’s team filed a lawsuit seeking to prevent the state from certifying the votes. One of the officials who tried to help Trump overturn the result is now the Republican candidate for Pennsylvania governor: far-right state Senator Doug Mastriano.

In Arizona, it’s Democratic Senator Mark Kelly versus Republican Blake Masters, a 36-year-old venture capitalist.

Arizona became a hotbed of denialism after Trump’s false claims of a stolen election. It’s now also home to two close midterm contests. Again, the first is for the Senate: Democratic Senator Mark Kelly (above right) versus Republican Blake Masters (left), a 36-year-old venture capitalist backed by billionaire entrepreneur Peter Thiel. The second is the governor’s race: former news anchor Kari Lake versus Arizona’s Democratic Secretary of State Katie Hobbs, who has come under fire for refusing to debate her feisty opponent. Lake, for her part, when asked on CNN’s State of the Union if she would accept the result of her election if she lost, simply said: “I’m going to win the election, and I will accept that result.”

Another personality worth watching here is Mark Finchem, who wants to be Arizona’s secretary of state. The self-described member of the Oath Keepers militia attended Trump’s rally on January 6 and believes the 2020 election was rigged. He’s also a chance to win, which would make him Arizona’s chief elections official, potentially working alongside Lake.

In Nevada, Catherine Cortez Masto is in a neck-and-neck battle against Republican challenger Adam Laxalt.

Nevada hasn’t backed a Republican presidential candidate since 2004 and Democrats hold both federal Senate seats, the governorship and three of Nevada’s four federal House seats. But in something of a surprise to Democratic strategists, the party’s grip on this south-western state is under threat, with incumbent Senator Catherine Cortez Masto in a neck-and-neck battle against Republican challenger Adam Laxalt, a former state attorney-general. In fact, Republicans now view Nevada as their best chance of picking up an extra seat in the Senate. Cortez Masto has been rallying support by focusing on abortion while Laxalt emphasises the economy. Also in Nevada, Jim Marchant – who has suggested House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer may not have won legitimate elections – is running for secretary of state.

In Ohio, the Trump-backed author of Hillbilly Elegy, J.D. Vance, is up against moderate working-class Democrat Tim Ryan.

Ohio used to be a critical swing state. Now, with Republican Senator Rob Portman retiring, it’s again a midterm battleground, between two starkly different candidates: the Trump-backed venture capitalist and author of the memoir Hillbilly Elegy, J.D. Vance (above left), and the moderate working-class Democrat Tim Ryan (right), who has run a strong campaign despite limited resources from his party, which initially viewed Ohio as a long shot. Vance was a Trump critic but dramatically switched to get endorsed by the former president, who recently boasted at a rally: “J.D. is kissing my ass.” Ryan, on the other hand, has gained ground partly by distancing himself from Biden on forgiving student loans, border control and other issues that don’t play well among the working-class voters of Ohio.

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