Pollsters have spent decades trying to puzzle out who will show up on Election Day, and several said the coronavirus pandemic has only made that challenge more difficult.

The polling and public opinion research industry has had to delay or alter the way it works amid stay-at-home orders and social distancing measures. Brock McCleary, president of Harper Polling, said he’s confident that polls will still be conducted — he’s working on a few himself — but voter behavior will get more mysterious.

Pollsters typically model turnout using statistical methods to estimate who will be a “likely voter.” However, that gets more difficult amid the pandemic as states postpone election dates and shake up voting methods to prevent the virus’ spread, McCleary said.

“Is it going to change people who are historically nonvoters into voters? Is it going to turn people who are traditionally only general election voters into primary voters because they’re bored?” he said.

McCleary, a GOP pollster, said the polls he has conducted have not seen much movement in fundamental political beliefs, outside of an across-the-board uptick in support for governors.

“It’s anyone’s guess how much staying power [the pandemic] will have except for the cases where the primaries are already on top of them,” McCleary said.

Terry Madonna, director of the Franklin and Marshall College Poll, said the pandemic has pushed pollsters to rethink how they model turnout, especially as events change from day to day. Last-minute surprises, such as a court ordering Wisconsin’s primary elections to move forward Tuesday, increase the challenge.

“We just don’t know what is going to happen in terms of when people are going to decide to vote or not vote,” Madonna said.

Madonna had to delay one poll he planned for March because Franklin and Marshall College closed its campus, and it took time to set up a remote call center. Those issues may have hamstrung other pollsters, too: Madonna pointed out only four polls have been taken in Pennsylvania so far this year — a low number for a battleground state in an election year.

Pennsylvania, like several other states, rescheduled its primary to June 2.

But several pollsters have been able to keep their schedule. The Monmouth University Polling Institute has conducted a pair of surveys since lockdowns started nationwide, according to director Patrick Murray.

He said he does not conduct “likely voter” screens in primaries but if the coronavirus crisis drags on, it could affect his general election modeling.

“I can’t change my methodology based on what we are guessing is going to happen. We have to see what happens,” Murray said.

‘Seismic’ shifts

Courtney Kennedy, the director of survey research at the Pew Research Center, said the pandemic’s spread caused a “seismic shift” in its approach to polls this year.

Kennedy said Pew scrapped a year’s worth of survey plans to take the virus into account. In some cases that meant adding more questions to an existing survey or changing how its teams work together.

“Polls are giving us some insight into the level of fear in the nation, the level of concern, people’s attitudes about all aspects of this,” Kennedy said.

Screening for people who are most likely to vote in this environment presents a unique challenge.

“That’s not just a moving target but an unknown target in terms of what the voting will be in the primaries or the general election,” Kennedy said.

Pew conducts its surveys through online panels, and Kennedy said response rates have already gone up. Many political pollsters use telephone surveys, which Madonna said can help get a more representative sample of an electorate.

Public opinion polls still may provide valuable insight into the electorate, Madonna said, even if they don’t help project who will vote.

“We can see how people feel about the job performances of how leaders have been handling the virus, what matters to voters now. I think we can get a reasonably good sense about that,” Madonna said.

As the pandemic threatens to drag on for months, it will be hard to say whether the health crisis will alter voters’ opinions by the general election, even if they have not changed so far.

“Are we still going to be dealing with coronavirus in September? October? Is the shadow going to loom that large?” McCleary said.