– In this election season of discontent, a lot of voters are having trouble committing.

Around 1 in 5 voters nationwide report themselves as undecided or flirting with third-party candidates, with the exact share depending on the poll and how the question is asked.

That’s far higher than in the last several elections, when fewer than 1 in 10 voters were still up in the air at this point, and reflects the distaste that large numbers of voters have for both Hillary Clinton and Donald Trump.

Those who remain uncertain include a couple of groups that may play an outsized role in determining the election’s outcome — young voters, many of whom loathe Trump but lack enthusiasm for Clinton, and college-educated suburban Republicans, who often find Trump scary but struggle with the idea of voting for a Democrat.

“I’m just lost,” Joanna Gianforcaro, 26, said on a recent afternoon as she sat with her mother at a farmers market in Doylestown, Pa., a swing area in a potentially important battleground state. Both women said they felt barraged by the negativity of the campaign and dismayed by the faults they perceive in both candidates. “I don’t find either of them genuine,” Gianforcaro said.

The large number of undecided voters probably won’t change until at least after the first presidential debate, scheduled for Sept. 26. Their prevalence has important consequences, both for the election itself and for the pre-election polls that voters will be hearing more and more about in the nine weeks between now and Election Day.

Trump causes concern and doubt among a lot of voters, but also inspires seemingly unshakable support from his core supporters. That ardor gives him an edge among voters who are most definite about their choice, according to the University of Southern California Dornsife/Los Angeles Times Daybreak poll.

Clinton, by contrast, wins among voters who are fairly certain but express some doubt either about their choice or whether they will cast a ballot, according to analysis of data collected since the poll began tracking the election in early July.

That suggests a key task for Clinton over the remaining weeks of the campaign is not so much persuading voters to her side, but motivating her soft supporters. The need to do so, in turn, helps explain the Clinton campaign’s seemingly insatiable appetite for cash, a lot of which is going to fund a vast — and expensive — get-out-the-vote operation in key states.

As for Trump, his apparent strategy of focusing on his core supporters, emphasizing the issues they care about most, as he did last week with his hard-line speech on immigration, may make considerable sense.

His advisers have suggested that they believe their best chance lies in a relatively low-turnout election in which lack of enthusiasm for Clinton holds down the Democratic vote. They also need to motivate a large number of blue-collar white voters who sat out the last election — a group that strongly supports Trump, but is less certain about voting, the poll data show.

In the most recent poll from the nonpartisan Pew Research Center, about 1 in 4 voters said they were undecided or didn’t know when asked to choose between Clinton and Trump.

Data from Pew and from SurveyMonkey, which polls thousands of voters each week on their presidential preferences, show younger voters much less certain of their vote than their elders. The SurveyMonkey numbers also show that Republicans, by a small but important margin, are more likely to be undecided than Democrats, reflecting the continued resistance to Trump within parts of the GOP.

A considerably larger group of voters remains at least somewhat uncertain about their choice. Only about 4 in 10 say they are sure of their candidate choice and certain to vote, according to the Daybreak poll.

Among that absolutely certain group, Trump leads 51 percent to 45 percent, the poll found. But broaden the lens to take in the nearly two-thirds of poll respondents who say they are at least fairly certain of their vote and their likelihood of casting a ballot, and the picture flips, with Clinton holding a 48 percent to 42 percent lead. Overall, the Daybreak poll shows the two locked in a dead heat.

In Lansdale, Pa., a longtime Republican expressed dismay about her party’s nominee.

“I think I’ll know when I get there,” said the woman, who would give only her first name, Evie, and her age, 67. “A lot of people are undecided,” she added. “I don’t think we’ll know till we go to the polls.”