Walter Mondale brandishes an infamous mistaken headline during an October 30, 1984 rally in Chicago.John Duricka / AP

A candidate or operative on a campaign that's losing has three options: despair; accept what’s happening and try to fix it; or deny. Right now, the Donald Trump campaign is exhibiting all three.

For despair, there are the staffers who are reportedly “suicidal” inside Trump Tower, and those who have simply quit. For acceptance, Trump himself has admitted he’s in trouble. But newly promoted campaign manager Kellyanne Conway is taking the denial route.

“Donald Trump performs consistently better in online polling where a human being is not talking to another human being about what he or she may do in the election,” she told the British outlet Channel 4. “It’s because it’s become socially desirable, if you’re a college educated person in the United States of America, to say that you’re against Donald Trump.”

Pressed to say how many voters might be included, Conway declined to elaborate but added, “I call it the undercover Trump voter, but it’s real.”

The idea is not new, and it’s commonly voiced by voters at Trump rallies these days. At the Republican National Convention, New York delegate Bob Hayssen told me, “There are millions of people out there that are afraid to admit they’re going to vote for Donald Trump.” Why not? “They’re going to get bashed by their liberal friends!”

Few phrases in politics are so mocked as the old standby, “The only poll that matters is on election day.” But when a trailing politician mouths that banal truth, she is at least acknowledging that the polling looks bad. The hope that some crop of hidden or undercover voters is waiting to save the candidate may be more deserving of mockery.

It is a wish with a long pedigree. The most famous example is the one where it really was true: Harry S Truman’s surprise victory of Thomas Dewey in 1948, memorialized with that headline. Gallup’s polling had shown Dewey leading by at least 5 points and sometimes as much as 11 since the start of August. The polling was wrong, and the president was reelected. Ever since, politicians who are in a hole have hoped the polls are simply bad. But Truman’s victory forced pollsters to reassess their methods, ironing out some of the problems that led to a misreading of the 1948 election, making it less likely that history would repeat itself.

In 1969, Richard Nixon warned that there was a “Silent Majority” that was opposed to the bra burners, anti-war protestors, and rioters in the streets. Trump has appropriated the phrase, repeatedly claiming that there’s a silent majority that supports him, too. But Nixon’s phrase wasn’t really a reference to elections—it was just about public discourse that he felt was dominated by a few noisy voices. And while they may have been silent, they weren’t invisible: Polls showed Nixon trouncing George McGovern ahead of the 1972 election, as he did. That didn’t stop McGovern from claiming hidden groups of voters would propel him to an upset victory. “We may see a thorough discrediting of the public-opinion polls in this campaign just as Harry Truman discredited them in 1948,” he said on the eve of an election in which he won just 17 electoral votes.

Via Nate Silver, here’s Democrat Walter Mondale in 1984, just a week before he lost by more than 18 points to President Ronald Reagan:

There's something going on in this country and the pollsters aren't getting it. Nobody who's been with me for the last few days and has seen these crowds, seen their response, seen their enthusiasm, seen the intensity of their response and how they respond to these issues, no one who's been where I've been, can help but believe that there's something happening in this country.

His speechwriter told The New York Times, “There's not a whiff of defeat because there's a conviction that something is happening that the polls aren't registering.”

Four years later, Democrat Michael Dukakis apparently hadn’t learned the lesson that crowd size means nothing. “I smell victory in the air, don't you?” he said in Kentucky. His wife and campaign manager forecast an upset. Robin Toner reported:

The crowds have been growing steadily—there were 10,000 in Sioux Falls, S.D., last week—and ever more spirited. They roar their encouragement, as if to deny the national polls showing their candidate trailing. It is hard to smell defeat amid the chanting and the cheers.

Dukakis lost by nearly eight points to George H.W. Bush.

Even Bob Dole, whose campaign against Bill Clinton was ailing so badly in 1996 that the Republican Party had diverted its resources to other races, indulged in the fantasy, as Adam Nagourney reported:

In the final hours of Bob Dole's campaign, the candidate took to appearing with a reproduction of a famous newspaper headline, which gave Mr. Dole hope in the face of discouraging polls. ''Dewey Defeats Truman,'' The Chicago Daily Tribune declared in 1948, the evening before Harry S. Truman won re-election to the Presidency.

At one rally, Dole joked, “I’m like Harry Truman. I’m from the Midwest, and I’m plainspoken, and I’m going to win whether you like it or not!” He didn’t.

Heading into the home stretch of the 2008 campaign, John McCain’s pollster released a memo making the case that “all signs say we are headed to an election that may easily be too close to call by next Tuesday.” The Wall Street Journal reported on where Bill McInturff believed the extra McCain votes were just waiting to come out of the woodwork:

“The strongest sub-groups for McCain are non-college men and rural voters of both genders,” McInturff said. The campaign has also seen more reason to hope that they will get more than a “20% chunk” of soft Democrats. “Wal-Mart women,” which the campaign describes non-college-educated women in households making less than $60,000 a year, are “swinging back solidly,” McInturff said.

Essential to this argument was a belief in the Bradley Effect, the idea that polling underestimates support for white candidates in elections with one white and one black candidate. (It’s named for Tom Bradley, an African American Los Angeles mayor who lost the 1982 California governor’s race to a white candidate despite leading in polls.) Mark Blumenthal wrote at the time that there was little evidence that there were a “hidden McCain vote,” and the election results bore him out.

Four years later, against a now-incumbent Barack Obama, Mitt Romney committed the same error. On Election Day, Romney arrived at the Pittsburgh airport, where he was met by a huge, cheering crowd. That’s what convinced him he’d win. He told reporters:

Intellectually I’ve felt that we’re going to win this, and I’ve felt that for some time. But emotionally, just getting off the plane and seeing those people standing there—we didn’t tell them we were coming. We didn’t notify them when we’d arrive. Just seeing people there, cheering as they were, connected emotionally with me.

Romney felt so good he didn’t even write a concession speech until that evening, when the writing was on the wall. Just as for McGovern, Mondale, and Dukakis, the crowd was a mirage, and Romney lost. A campaign adviser told CBS that running mate Paul Ryan was “genuinely shocked.” In his case, it turned out there had been a hidden vote—but it was for Obama. The Romney campaign underestimated the number of minority voters who would turn out.

That brings us to 2016, and Conway’s belief in the hidden voter. That belief has proven to have a pretty bad track record in the past. But could it be vindicated this November?

Conway’s case depends on “social desirability bias,” the idea that Trump voters are reluctant to admit that they support their candidate because they might be judged by friends, family, and neighbors for it. From a certain point of view, the idea that even his own supporters deny him might look like further evidence that Trump is in trouble, though to its proponents, this is just evidence of how effectively the noisy majority bullies the silent majority, forcing them to succumb to the mores of political correctness that Trump and his supporters so despise.

Earlier in the campaign, it was true that Trump’s support was higher in scientific online surveys (i.e., not those polls on random news websites) than in telephone surveys. But as Nate Cohn wrote, the live phone surveys were also more accurate reflections of Trump’s support.

Meanwhile, a host of smart poll analysts have explained in detail why it doesn’t look like there’s a chunk of voters who are missing or simply lying about who they support. Trump may have a path to victory by winning a tremendous portion of white voters. Sean Trende was arguing long before the Trump phenomenon that there was a large cache of “missing white voters” who a Republican candidate might be able to turn out and ride to victory. But there’s no sign that Trump is building the sort of large and sophisticated voter identification and turnout operation it would require to get a large group of infrequent voters to the polls—or even to make sure regular voters show up. On the flip side, it’s not all that surprising that a candidate who has gone out of his way to offend many groups of Americans would be struggling in the polls.

As for the thousands turning out at rallies, Trump has bragged for months about his crowds. More recently, his tune has changed somewhat. “I don’t know why we’re not leading by a lot. Maybe crowds don’t make the difference,” he said in Florida in early August. That’s more than career politicos from McGovern to Dukakis to Romney were willing to admit.

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