There are several races on the ballot this fall that will have profound consequences for American democracy. In several states, Republican candidates who doubt the election 2020 election results, or in some cases actively worked to overturn them, are running for positions in which they would have tremendous influence over how votes are cast and counted. If these candidates win, there is deep concern they could use their offices to spread baseless information about election fraud and try to prevent the rightful winners of elections from being seated.

Here’s a look at some of the key candidates who pose a threat to US democracy:

Doug Mastriano

Mastriano, the Republican nominee for governor in Pennsylvania, played a key role in efforts to overturn the 2020 election. He was the “point person” for the Trump campaign in Pennsylvania as lawyers put together fake slates of electors for Trump, according to emails obtained by the New York Times. He also organized an event with Rudy Giuliani after the 2020 election in which speakers spread misinformation about the 2020 election. He hired buses and offered rides to the US Capitol on January 6 and was there himself. He has supported the idea of decertifying the presidential race in Pennsylvania, a key battleground state, which is not possible.

If elected, Mastriano would wield considerable power over elections in Pennsylvania. The state is one of a handful where the secretary of state, the chief election official, is appointed by the governor. Mastriano has said he has already picked someone, but hasn’t said who. The Philadelphia Inquirer has speculated he could pick Toni Shuppe, an activist who has spread voting misinformation and theories linked to the QAnon movement. Mastriano has also said he would decertify election equipment and cause all voters in the state to re-register to vote.

Mark Finchem

Finchem is the Republican nominee for Arizona secretary of state, which would make him Arizona’s chief election official. Finchem, a member of the Oath Keepers, was at the US Capitol on January 6. He introduced a resolution earlier this year to decertify the election. In 2020, he was one of several lawmakers who signed a joint resolution asking Congress to reject electors for Joe Biden.

He has said, falsely, that Joe Biden did not win the election in Arizona in 2020, which is false. “It strains credibility,” he told Time magazine in September of Biden’s victory. “Isn’t it interesting that I can’t find anyone who will admit that they voted for Joe Biden?” When a reporter asked him whether it was possible that people he didn’t know voted for Biden, Finchem said: “In a fantasy world, anything’s possible.”

Kari Lake

A former news anchor with no prior political experience, Lake made doubting the 2020 election a centerpiece of her successful bid to win Arizona’s GOP nomination for governor.

If she wins the governor’s race, Lake would be one of the statewide officials charged with certifying the results of the presidential election. She has called the 2020 election “corrupt and stolen” and said she would not have certified it. She joined an unsuccessful lawsuit to require ballots in Arizona to be counted by hand, which experts say is unreliable and costly. She has backed ending mail-in voting, which is widely used in Arizona.

Jim Marchant

Marchant is the Republican nominee for secretary of state in Nevada. He is linked to the QAnon movement; he has said he was pushed to run for the position by Trump allies and a prominent QAnon influencer. He leads a coalition of far-right candidates seeking to be secretary of state in key battleground states.

He lost a 2020 congressional race by more than 16,000 votes, but nonetheless challenged the result by alleging fraud. He has since traveled around the state pressuring counties to get rid of electronic voting equipment and instead only hand-count paper ballots. Such a switch would be unreliable – humans are worse at counting large quantities of things than machines – as well as costly, and take a long time, experts say. He has falsely said voting equipment is “easy” to hack and said that Nevadans’ votes haven’t counted for decades. He has claimed there is a global “cabal” that runs elections in Nevada and elsewhere.

Kristina Karamo

Karamo, the GOP nominee for secretary of state, became nationally known after the 2020 election when she claimed she witnessed wrongdoing as ballots were being counted in Detroit. The allegations were debunked, but Karamo, a community college professor who has never held elective office, went on to rise in conservative circles. She appeared on Fox News and was a witness at a high-profile legislative hearing about election irregularities. She joined an unsuccessful lawsuit to try to overturn of the election. She has claimed “egregious crimes” were committed during the 2020 election and said on a podcast: “It’s time for us decent people in the Republican party … to fight back. We cannot have our election stolen,” according to Bridge Michigan.

She has also come under fire for comments on her podcast comparing abortion to human sacrifice and opposing the teaching of evolution in schools, according to Bridge Michigan.

Matthew DePerno

DePerno, a lawyer who has never held elected office, became a celebrity in conservative circles for his work after the 2020 election. He helped lead a lawsuit in Antrim county, in northern Michigan, where a clerk made an error and posted incorrect information on election night. He claimed election equipment was corrupted, and a judge authorized an investigation of the county’s election equipment that became the basis of an inaccurate report that Trump allies used to spread misinformation about the election. A Republican-led inquiry into allegations of fraud found his actions to be “​​misleading and irresponsible”. DePerno has said he would arrest Jocelyn Benson, a Democrat serving as Michigan’s top election official, as well as Dana Nessel, his Democratic opponent in the attorney general’s race.

DePerno also faces potential criminal charges for unauthorized access to voting equipment. A special prosecutor is investigating the matter.