At a Republican convention in Dallas this month, President Trump asked elected officials and supporters to raise their right hands. Then he led them in a pledge: to vote this November, registered or not, and to “cheat like hell, like they do.”

His defenders will call it a joke. But his administration has been acting as if he meant it. The Justice Department has filed lawsuits against 30 states and the District of Columbia demanding their voter rolls. F.B.I. agents carted away more than 650 boxes of election records in Fulton County, Ga., as part of a criminal investigation into the 2020 election. Homeland Security agents subpoenaed Macomb County, Mich., for its records on noncitizen voters.

Someone has to stand up to that pressure, and in most states that someone is the secretary of state. Michigan’s secretary of state, Jocelyn Benson, refused the Justice Department’s demand for the state’s voter rolls, and won her case in federal court. In Texas, the secretary of state at the time, Jane Nelson, handed over records on 18 million voters voluntarily.

This November, in races few people are watching, four of seven swing states will elect a secretary of state. The winners take office in January and will run the presidential election of 2028. Whether that election ends in a constitutional crisis depends on who they are, and the candidates are alarming.

I have spent decades working to elect secretaries of state. These officials tend to serve as their state’s chief election officer: They maintain the statewide registration list, oversee the voting machines, write the mail-ballot rules and often certify the count itself. We call this “election administration,” a phrase that undersells the power involved. A decision to send fewer voting machines to urban precincts or to purge eligible voters from the rolls can change an election’s outcome. The secretary of state reports to no one but the voters.

In my years of focus groups and polling, Democrats, Republicans and independents have said the same thing: They want honest, competent, nonpartisan secretaries of state running their elections. Yet in the four swing states choosing one this year, look closely at who is asking for the job.

In Arizona, Republicans chose Alexander Kolodin, a lawyer whom the state bar put on probation for his role in one of the lawsuits trying to overturn the 2020 election. He represented some of the Republicans who signed a certificate declaring Mr. Trump the winner in Arizona, which he lost, and asked the State Supreme Court to ban absentee voting. Now he wants to run Arizona’s elections.

In Nevada, the Republican Jim Marchant says he would not have certified his state’s valid 2020 result. When he lost his own race for Congress that year, he sued to request a new election, which a judge rejected. He says he would end Nevada’s universal mail voting and force every voter to register again: a purge by paperwork.

In Georgia, the Republican nominee, Tim Fleming, has never said publicly that Joe Biden won the state, acknowledging only “irregularities.” Mr. Fleming sponsored a law that lets counties deploy fewer voting machines.

And in Michigan, where presidential elections are so often decided, the Republican candidate, Anthony Forlini, hired a Jan. 6 ringleader to train poll workers; she had been filmed outside the Capitol urging the crowd to “storm the gates.”

Not one of those candidates appears to believe that the vote speaks for itself.

Since 2020, Republican primary voters have picked nominees based on how willing they were to declare the last election stolen. Republicans grasped decades ago that the office was worth fighting for, and they recruited candidates, funded them and won while Democrats, until recently, treated the job as an afterthought.

We have seen before how outside pressure tests these secretaries of state. In the 2020 election, the vote count in Arizona ran for days while a crowd, some of them armed, amassed outside the Phoenix counting center. After the secretary of state, Katie Hobbs, signed the certification, protesters threatened her at her home.

In Michigan, Ms. Benson defended her state’s certified result as armed protesters gathered outside her house, where she and her 4-year-old son were hanging Christmas decorations. That same winter, Georgia’s secretary of state, Brad Raffensperger, spent an hour on the phone with Mr. Trump, who asked him to “find 11,780 votes.” He declined.

Those three officials were what stood between a contested election and a constitutional crisis. They followed the law, honored the will of the people and said no.

Even if one of these four candidates in Arizona, Nevada, Georgia or Michigan wins this year, and a call to “find some votes” comes again in 2028, their records suggest they would acquiesce. And the day they do, we can expect to see dueling counts, dueling certificates, a presidency in dispute and a nation in constitutional crisis.

We are choosing who will run the next presidential election. If we do not pay attention now, the American people may not be the ones who decide who wins it.

Ellen Kurz is the founder and president of iVote, a national voting rights group. This article originally appeared in The New York Times.