Polls show substantial support for candidates like RFK Jr. How much of it is real?

Historical precedent suggests the election performances of third-party and independent candidates rarely live up to their pre-election polling.

Third-party and independent candidates like Robert F. Kennedy Jr. are making an unusually strong showing in early polls of this fall’s presidential race – a finding that not only highlights a strain of dissatisfaction with Joe Biden and Donald Trump but also adds further uncertainty to what is shaping up to be a close contest between them. Across five national polls released in March and April – from Quinnipiac University, Fox News, Marquette Law School, NBC News and Marist College – Kennedy received an average of 13% support for his independent presidential bid when his name was explicitly included in the survey question, with independent candidate Cornel West and Green Party candidate Jill Stein taking an average of 3% each. Given the narrow margin between Trump and Biden, who are effectively deadlocked in many surveys, even a fraction of that support could prove crucial to the election’s outcome. Historical precedent, however, suggests that third-party and independent candidates’ election performances rarely live up to their polling. “When people tell us that they’re going to vote for a third-party candidate, they’re actually telling us one of two things,” said Dan Cassino, the executive director of the Fairleigh Dickinson University Poll, who has researched the overestimated support for such candidates in surveys. “Some proportion are saying, ‘I hate both of the major party candidates, and I’m going to illustrate that by saying that I’ll vote for literally whoever you put in the third spot (whether I’ve heard of them or not).’ Others are saying, ‘I really like that third party candidate, and I’m going to vote for them!’” Given the relative unpopularity of this year’s two major presidential candidates, Cassino noted, the first group – those who treat being polled as an opportunity to vent their discontent with the system – are likely to far outnumber those who are fully committed to backing a specific alternative. In a national CNN poll last year, 39% of voters who said they would support Kennedy for president also said, in a separate question, that they didn’t know enough about the candidate to offer an opinion of him. But finding the right questions to disentangle those sentiments is difficult, and past polling has frequently struggled to estimate the support for such challengers. In the 2014 midterms, most surveys overstated the eventual support for third-party candidates. But while pre-election polls that asked voters about third-party candidates by name tended to inflate their support, those that omitted them often underestimated it, according to data compiled by Joe Lenski, the executive vice president of Edison Research. Estimations of third-party support were less accurate further out from Election Day, the report also found.