Arizona governor: Katie Hobbs (D) v Kari Lake (R)

Hobbs is currently secretary of state in what used to be a Republican stronghold. Lake is a former TV news anchor who relishes sparring with the media and promoting Donald Trump’s false claim that the 2020 election was stolen. Victory for Lake – who has appeared with figures linked to QAnon on the campaign trail – would be a major boost for the former president and ominous for 2024.

Arizona secretary of state: Mark Finchem (R) v Adrian Fontes (D)

Secretary of state elections have rarely made headlines in past midterms but this time they could be vital to the future of American democracy. The battle to become Arizona’s top election official pits Fontes, a lawyer and former marine, against Finchem, who falsely claims that voter fraud cost Trump the state in 2020 and who was at the US Capitol on January 6 2021.

Arizona Senate: Mark Kelly (D) v Blake Masters (R)

Kelly is a retired astronaut who became well known in the state when his wife, then-congresswoman Gabrielle Giffords, was shot and critically injured at an event in Tucson in 2011. Masters, a 36-year-old venture capitalist and associate of mega-donor Peter Thiel, gained the Republican nomination with the help of Trump’s endorsement but has since toned down his language on abortion, gun control and immigration.

Florida attorney general: Aramis Ayala (D) v Ashley Moody (R)

Ayala is the first Black female state attorney in Florida history. Moody, the incumbent, is a former prosecutor and judge who recently joined 10 other Republican attorneys general in a legal brief that sided with Trump over the justice department regarding the FBI search of his Mar-a-Lago home. Like her predecessor Pam Bondi, Moody could be a powerful ally for Trump as the state’s top law enforcement official.

Georgia governor: Stacey Abrams (D) v Brian Kemp (R)

Abrams, a voting rights activist, is bidding to become the first Black female governor in American history. But she lost narrowly to Kemp in 2018 and opinion polls suggest she could suffer the same fate in 2022. Kemp now enjoys the advantages of incumbency and a strong state economy. He also has momentum after brushing aside a primary challenge from Trump-backed challenger David Perdue.

Georgia Senate: Herschel Walker (R) v Raphael Warnock (D)

Warnock’s victory in a January 2021 runoff was critical in giving Democrats’ control of the Senate. Now the pastor of Atlanta’s Ebenezer Baptist church – where Martin Luther King used to preach – faces Walker, a former football star with huge name recognition but scant experience (he recently suggested that China’s polluted air has replaced American air). Polls show a tight race between the men, both of whom are African American.

Ohio Senate: Tim Ryan (D) v JD Vance (R)

The quintessential duel for blue-collar voters. Ryan, a Democratic congressman, has run an energetic campaign, presented himself as an earthy moderate and accused Vance of leaving the state for San Francisco to make millions of dollars in Silicon Valley. Vance, author of Hillbilly Elegy, seen as a kind of Rosetta Stone for understanding the Trump phenomenon in 2016, used to be a Trump critic but has now gone full Maga.

Pennsylvania governor: Doug Mastriano (R) v Josh Shapiro (D)

Mastriano, a retired army colonel and far-right state senator, led protests against pandemic restrictions, supported efforts to overturn Trump’s 2020 election defeat and appearing outside the US Capitol during the January 6 riot. Critics say that, as governor, he could tip a presidential election to Trump in 2024. Shapiro, the state’s attorney general, is running on a promise to defend democracy and voting rights.

Pennsylvania Senate: John Fetterman (D) v Mehmet Oz (R)

One of the most colourful duels on the ballot. Fetterman, the state’s lieutenant governor, is 6ft 8in tall, recovering from a stroke that has affected his speech and hearing, and running aggressive ads that mock Oz for his lack of connections to the state. Oz, a heart surgeon and former host of the daytime TV show The Dr Oz Show, benefited from Trump’s endorsement in the primary but has since backed away from the former president’s claims of a stolen election.

Wisconsin Senate: Mandela Barnes (D) v Ron Johnson (R)

This is Democrats’ best chance of unseating an incumbent senator: Johnson is the only Republican running for re-election in a state that Biden won in 2020. First elected as a fiscal conservative, he has promoted bogus coronavirus treatments such as mouthwash, dismissed climate change as “bullshit” and sought to play down the January 6 insurrection. Barnes, currently lieutenant governor, is bidding to become the first Black senator in Wisconsin’s history.