The plan was for an expert cybernavigator to teach Minnesota election workers how to combat foreign cyber­­attacks and domestic disinformation campaigns that could wreak havoc on the 2020 elections.

A statewide training session scheduled at Camp Ripley later this month would have featured simulated attacks of the sort that U.S. intelligence officials detected in 2016.

But COVID-19 has overwhelmed all of that. The training, like all large gatherings, is on hold.

Instead, election officials are steeling themselves for a possibly greater problem presented by the coronavirus itself, which already has forced the postponement of several presidential primaries and could severely hamper turnout in the fall general election.

The nation received a foreshadowing of that possibility last week in Wisconsin, where the virus prompted the closing of many polling places. Forced to choose between their personal safety and civic duty, many would-be voters stayed home. Others, wearing masks and doing their best to keep a safe distance from one another, waited in sometimes hourslong lines taking their chances to cast their ballots.

Eager to avoid more such scenes, Democrats in Minnesota and Washington, D.C. — led by U.S. Sen. Amy Klobuchar — have responded with calls to promote mail-in and early voting, measures that have run into resistance from President Donald Trump and many Republicans across the country, including lawmakers in St. Paul, who have raised questions about ballot integrity.

With local primary elections looming in Minnesota in August and national elections in November, the pandemic has raised the stakes in the long-running battle over ballot access and election security.

Klobuchar and fellow Democratic Sen. Ron Wyden of Oregon unveiled federal legislation last month that would ensure early voting in all states, as well as voter access to mail-in and absentee ballots. Last week, the senators were joined by secretaries of state from both parties to call for more federal funding and quick action on voting by mail.

“We also have to think beyond the horror of the day, months ahead of us,” Klobuchar said Thursday. “And to do that we have to start planning now. We don’t know what the status of this virus will be in November, we don’t know what it will be in August.”

Advocacy groups such as the Brennan Center for Justice in New York argue that mail-in voting is already deeply entrenched in American politics. More than a quarter of ballots were cast by mail in 2018. Five states — Hawaii, Utah, Oregon, Washington, and Colorado — will hold all-mail elections this year. And in 28 states and the District of Columbia, voters have the right to request a mail ballot without excuse. Voting by mail is also the standard way for members of the armed services to participate in elections.

Minnesota Secretary of State Steve Simon proposed legislation last week that would temporarily move the state to mail-in balloting and shift polling locations away from vulnerable populations such as senior care facilities — measures backed by the Minnesota DFL.

“I think there is that danger if people perceive that they have to choose between their health and their right to vote, they’re probably going to choose health,” said Simon, a Democrat. “We think that’s a false choice, and we want to come up with a method of voting that doesn’t force anyone’’ to make that choice.

March primaries in Florida, Arizona and Illinois saw significant drops in in-person voting amid fears of the spreading virus. Wisconsin’s Supreme Court rejected Gov. Tony Evers’ order to postpone in-person voting.

The issue has only deepened partisan fissures.

Minnesota is poised to get up to $7 million out of $400 million Congress sent to states for election-related purposes as part of the $2 trillion aid package. Democrats and election security advocates say far more is needed to expand voting by mail and other early voting measures. However, Minnesota Republicans sharply opposed Simon’s proposals last week.

“Don’t be fooled folks,” Minnesota GOP Chairwoman Jennifer Carnahan wrote on Twitter. “This is an effort to steal our free and fair process to win elections.”

Trump, in an interview last month on Fox News, criticized mail-in and early voting provisions that Democrats had proposed in the federal aid package. “The things they had in there were crazy,” Trump said. “They had things — levels of voting that, if you ever agreed to it, you’d never have a Republican elected in this country again.”

However, the GOP is not uniformly opposed to voting by mail. It’s long been the practice in Utah, a Republican-dominated state, and in recent days the GOP governor of Nebraska has supported it while the party in Pennsylvania has urged people to vote by mail.

Simon and his allies say time is running out to make needed changes ahead of the November election. He’s also concerned about turnout in Minnesota’s August primary for legislative and congressional seats.

A Pew Research Center poll last month found that about two-thirds of Americans say they would be uncomfortable going to a polling place during the virus outbreak. And a new Reuters/Ipsos poll found that 72% of all U.S. adults, including 79% of Democrats and 65% of Republicans, supported mail-in ballots as a way to protect voters against the pandemic.

A new bipartisan national task force on election security also recently urged election officials to immediately begin preparing for a crush of absentee voting requests, regardless of whether the pandemic’s spread slows.

Simon said that short of mailing ballots to every voter this year, the state might at least encourage voters to request mail-in ballots. But several influential state GOP lawmakers see little need to change the rules.

“I think mostly we’re just in a good place, period,” said state Sen. Mary Kiffmeyer, a Big Lake Republican who chairs the Senate’s finance, policy and elections committee. “We have a high voting population that is not easily deterred, and civic engagement and participation.”

Kiffmeyer, a former Minnesota secretary of state, argues that any measures to expand mail-in voting are premature given the “state of flux” during the pandemic.

Any new federal election security money must clear Kiffmeyer’s committee before the Legislature can approve its use by Simon’s office. A previous round of security money prompted a bitter fight that extended into the final hours of the 2019 session.

Absent legislative action, Gov. Tim Walz could order changes to the 2020 election in response to the corona­virus emergency. Michigan Gov. Gretchen Whitmer, a Democrat, last month issued an executive order encouraging residents to vote absentee.

Either way, money will be needed for extra postage, envelope sorting and staffing if mail-in voting is expanded. Simon says he is also worried about a shortage of poll workers if the pandemic persists. He noted that election workers already have been dropping out of three upcoming special school district elections, a development he called the “canary in the coal mine.”

“These are pretty small-scale elections,” Simon said. “So if someone is afraid in what will probably be a pretty low-turnout election to show up and sit for 13 hours in a polling place, imagine the reticence or fear for a presidential general election in November with high turnout and high energy.”