ALLENTOWN, Pa. — Mary Heintzelman shakes her head in disgust over the presidential election.

“I don’t think we have a candidate that’s really suitable to be president in either party,” says Heintzelman, an administrative assistant from Whitehall, Pennsylvania. Her son suggests she write in a candidate when she votes in November, but the 68-year-old says despondently, “I don’t even know who to write in.”

Heintzelman is hardly alone in her angst over the prospect of a November matchup between presumptive Republican nominee Donald Trump and likely Democratic pick Hillary Clinton. While 65 percent of Americans say they’re interested in the White House race, just 23 percent say they’re excited as the contest shifts from the primaries to the general election, according to a poll by the Associated Press-NORC Center for Public Affairs Research.

The malaise crosses party lines. Majorities of Republicans and Democrats say the election has left them angry, helpless and frustrated. Only 13 percent of Americans say they’re proud of what has transpired in a campaign where surprising candidates have thrived and Trump in particular has defied political norms.

Election experts say the gap between Americans’ high interest and low excitement makes the race to succeed President Obama highly unpredictable.

Turnout can be low when unpopular candidates are on the ballot, but the unusual nature of a race between a billionaire businessman who has never before sought elected office and a former first lady who would be the first female president could offset voters’ sour mood.

“We’re in uncharted territory here with these two candidates,” said Michael McDonald, a political science professor at the University of Florida who said “the negativity gives people something to talk about.”

“If people perceive the election is interesting, they may still show up to vote even if it’s against a candidate,” McDonald added.

Former Gov. Ed Rendell, D-Pa., predicted voter enthusiasm could increase as the general election heats up, particularly when the nominees meet in debates.

“I do believe in some ways there’s a reset in the general election,” Rendell said. “First of all, you have some voters that paid no attention and only vote in general elections. Secondly, even the ones who paid attention, now all of a sudden there’s two candidates and six months.”

For now, though, some people say they’re resigned to an election in which they’ll be voting against a candidate instead of for one. That view was pervasive in interviews with more than 30 voters interviewed by the AP in Pennsylvania. Democrats have carried the state in every presidential election since 1992, but Trump’s campaign hopes strong support from working-class white voters could swing the state back to the Republicans.

“Your vote isn’t who you’re for, it’s who you don’t want in,” Joann Spangenberg, a 48-year-old loan underwriter. “It shouldn’t be that way.”

Trump formally clinched the GOP nomination last week, cementing his extraordinary rise to the top of the Republican Party. Clinton is still trying to shake Sanders, but it’s nearly impossible for Sanders to catch the former secretary of state in the Democratic delegate count.

For Ron Zemlansky, a 64-year-old accountant from Catasauqua, an election between Trump and Clinton leaves voters with two bad options.

“Trump, I don’t think he’s qualified,” he said. “Hillary, there’s too much baggage.”

Despite voting for Obama twice, Zemlansky said his questions about Clinton may push him to Trump.

“Right now, I hate to say it, I’d probably pick Trump,” he said.

The AP-NORC poll of 1,060 adults was conducted May 12-15 using a sample drawn from NORC’s probability-based AmeriSpeak panel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 4.1 percentage points.