SEATTLE (NYTIMES) - Elections are complicated events, involving massive amounts of paperwork, thorny issues of law and a widely scattered cast of poll workers and ballot counters.

In Washington state, which is holding its 2020 primary on Tuesday (March 10), there is another matter that officials are having to consider this year.

"How long does coronavirus last in saliva that is on an envelope?" asked Ms Kim Wyman, the secretary of state in Washington, the state hardest hit by the virus so far.

Washington votes by mail, which eliminates most concerns about viral transmission, but also creates some.

"We're telling all of the people who handle incoming ballots to use gloves," Ms Wyman said. "We've also had a recommendation from the National Guard: 'Folks, you might consider masks.'"

Voters have been advised to use a wet sponge or cloth to seal envelopes rather than licking them. But many were probably mailed in before it was clear how big a virus risk there was in the state.

The leading Democratic presidential candidates, Mr Joe Biden and Mr Bernie Sanders, both addressed questions on Sunday about how the virus might affect their travel and campaigning.

Public health officials have said adults over 60 are most at risk and should avoid crowds. Mr Biden is 77. Mr Sanders is 78. President Donald Trump is 73.

Mr Biden's campaign, in a statement, criticised Mr Trump for contradicting public health guidance and said the Biden campaign "will lead by example in following expert advice and complying with reasonable risk mitigations".

Mr Sanders, asked by CNN host Jake Tapper whether he, Mr Trump and Mr Biden should all limit their travel and avoid crowds, replied: "In the best of all possible worlds, maybe. But right now, we're running as hard as we can."

Washington's voting challenges would pale in comparison with those facing the nation if the virus continues to spread and particularly if it is still a public health risk in November.

A presidential election unfolds over months in crowded campaign rallies and nominating conventions, and culminates in November when more than 130 million voters and nearly one million poll workers come together in firehouses and gymnasiums, swiping fingers on touch screens or opening up those aforementioned licked envelopes.

The effects of a socially transmitted respiratory virus, if it were to spread unabated through campaign season, would be almost endless.

Just how big a public health emergency the virus will become remains unknown.

But the virus is already affecting the primaries in complications for voters overseas, cancelled party fundraisers and polling places that opened late on Super Tuesday because worried poll workers failed to show up.

And if the outbreak continues to grow and intensify, or if, like the 1918 influenza, the contagion abates and then comes roaring back in the fall, it may soon be too late to do anything about it before the presidential election.

"The problem is, we don't have a plan for what happens if a part of the country faces a disruption on a presidential Election Day," said Dr Rick Hasen, an election law expert at the University of California, Irvine's law school.

He said Congress should be considering federal legislation right now that would address potential voting trouble.

"What if one part of the country is affected, if it's California or Florida?" he said. "The closer we get to the election, the harder it's going to be to come up with rules that look fair."

This was indeed a factor in the 1918 election, which was not a presidential year but was plagued by issues nationwide involving quarantines and emergency measures.

Mr Al Smith, running as a Democrat for governor of New York, accused local Republican officials of calling last-minute bans on public gatherings to tamp down his support rather than to prevent the spread of flu, according to a 2010 study of that election year.

The outcome of a local judicial race in Idaho was eventually overturned in part because special arrangements were made to allow a small group of people under quarantine to vote.

Unusual arrangements were in place in the Israeli elections last Monday, with special plastic-tented polling stations set up for voters in quarantine.

Lines there were reported to be long, and officials initially baulked at counting the ballots cast there. But even short of exceptional measures like these, officials are already having to consider a long list of potential problems.

"What happens if all your poll workers get sick?" asked Secretary of State Matthew Dunlap of Maine, raising a possibility that could worsen an already serious shortage of willing poll workers, who tend to be older people and thus much more vulnerable to the disease.

"If this thing continues to spread and grow, then you have to figure out how to compensate for that."

Mr Edmund Michalowski, the deputy clerk for elections in Cook County, Illinois, which includes Chicago, said his office was meeting with a local judge to seek an order that would expand the office's ability to take certain measures that usually require piecemeal judicial approval - like extending voting hours, reassigning early polling locations, changing voting days - in the event of "extraordinary circumstances".

He also added that officials have also been looking at effective disinfectants to wipe down touch screens between each vote.

For now, much is still in the discussion stage. Even as other major gatherings have been cancelled or put on hold, Democrats on the campaign trail have kept speaking to big crowds - at a rally last Monday for Senator Bernie Sanders, Representative Ilhan Omar asked people in the crowd to hold hands - and even the famously germ-averse Mr Trump has brushed off concerns about his own big rallies, calling them "very safe".

The Republican and Democratic national committees have begun talking of alternate plans for the conventions this summer when, depending on what is happening with the outbreak, it might not be a great idea for 50,000 people from around the country to crowd into a big room.

But officials stress that there have been no major changes yet to the original plans.

"Every convention necessitates developing a number of contingency plans to provide for a variety of scenarios," Mr Joe Solmonese, the chief executive of the Democratic National Convention Committee, said in a statement.

"We will continue to monitor this developing situation closely and follow the guidance of the CDC and state and local health officials."

In a briefing with reporters last Monday, Mr Max Everett, the vice-president of the Republican National Convention Committee, said organisers were "constantly looking at all sorts of different things we've got to look at, to make sure we have all our contingencies planned for well ahead of time".

Major changes to the conventions could be a headache for both parties - for the Republicans, given Mr Trump's fondness for pageantry, and particularly for the Democrats, given the prospect that their party may need some unifying after a divisive primary.

Some infectious disease experts insisted that the most drastic scenarios were unlikely and that cancelling a convention would be a serious overreaction.

"I would recommend people travel, go ahead and go and have this thing," said Dr Herbert DuPont, the director of the Centre for Infectious Diseases at the University of Texas School of Public Health, who believes a panicked response could be more disruptive than the virus itself.

Such anxiety, he added resignedly, has already "produced distrust of our government - and it's going to affect, big time, this election".

That is precisely what troubles those who watch election security closely. The coronavirus does not need to be severely damaging for the deep concerns about it to present risks that could be exploited by outside actors.

"The individual decision to go vote is much more vulnerable than the ballot itself," said Mr Yonatan Striem-Amit, a founder of Cybereason, a cyber security technology company.

Presidential elections can hinge on small changes in turnout in certain areas, and turnout at that level could be easily manipulated in anxious times by someone running a misinformation campaign.

A rumour spreading on social media about a local outbreak on Election Day, even if quickly proven to be false, could be enough to swing a precinct.

"As an attacker, all you really have to do is target voters in a small, geographically concentrated area and try to convince them it's not worth it to get out of the house and vote," Mr Striem-Amit said.

There is evidence that this may already be happening.

Mr Michalowski said the Cook County Clerk's office had recently reminded people that mail-in ballots were available for early voters.

Immediately, he said, there came "a swarm of Facebook posts saying, 'Don't ask for a mail-in ballot because it is only going to come in a foreign language'."

That just wasn't true, he said.

The concern about politically motivated misinformation campaigns underscores a larger point: For all the potential effects of the coronavirus on the mechanics of the voting process, it can also affect the outcome of the vote itself. That could happen in Tuesday's Washington primary.

The polls show a dead heat in the state's Democratic presidential contest, but neither Mr Biden nor Mr Sanders has scheduled any appearances in Washington in the days before the election.

Neither candidate directly addressed on Sunday the question of travel to Washington.

State Democrats had expected presidential candidates to attend the party's annual Warren G. Magnuson Awards dinner this past Saturday.

But the dinner, which had been billed as "the single biggest event in Washington State Democratic Party history", was postponed because of the health fears.

And the virus and the response to it could affect individual voters' choices.

Ms Lisa Cominetti, 55, a business analyst for the University of Washington continuing college programme, sees the Trump administration's handling of the coronavirus as another reason behind her commitment to elect a Democrat in the fall.

"That person in office is not qualified to be in office," she said.

Mr John Anderson, 72, a retired engineer, said Mr Trump's handling of the coronavirus outbreak had reinforced his decision to support him.

"It seemed like he was right away reacting to the need and getting experts together," Mr Anderson said.

"The Democrats seemed like they were all over the map, fighting each other and just taking shots at Trump instead of trying to be supportive."