Republicans Often Outperform Polls in Presidential Elections

With just four days until the 2024 election, former President Donald Trump is leading in national polls for the first time in his three campaigns for the White House. While Trump previously lost the popular vote twice, he did outperform the polls in 2016 by 1.1 points and in 2020 by 2.7 points.

Polling data from RealClearPolitics, available since 2004, shows that Republicans have often surpassed poll predictions. In 2004, former President George W. Bush led Democratic challenger John Kerry by 1.5 points in the polls but outperformed expectations, winning the popular vote by 2.4 points, a margin of 0.9 points above the polls.

Former President Barack Obama was projected to defeat John McCain by 7.6 points in 2008; while McCain lost by a significant margin, he outperformed the polls by 0.3 points. In 2012, however, polls predicted a much closer race, with Obama projected to win over Mitt Romney by 0.7 points, though he ultimately won by 3.9 points.

Pollster David Shor of Democrat-aligned Blue Rose Research has suggested that polls generally lean in favor of Democrats due to “partisan nonresponse” — a trend where certain groups of Republicans are less likely to respond to surveys than their left-leaning counterparts. Shor pointed to early voting in 2020, noting that “early voters were considerably less Democratic than people thought.” Current early voting data for 2024 similarly shows Democrats turning out at lower-than-expected rates.

Trump has suggested that pollsters may have ulterior motives. He claimed on the Joe Rogan Experience podcast that some polling numbers are intentionally adjusted to make key races look less competitive, potentially discouraging Republican turnout on Election Day.

Election betting markets, which have historically been reliable predictors, currently give Trump a 60.6% chance of defeating Vice President Kamala Harris. Polymarket, the most popular election betting platform, gives Harris a 62% chance to win the popular vote, while Trump’s national polling lead is just 0.3 points.

Research from ElectionBettingOdds.com founder Maxim Lott shows that betting odds tend to slightly favor Democrats, although less than models like FiveThirtyEight do. Both betting odds and models have generally been “surprised” by Republican wins.

In the battleground states, Trump is currently favored in five of seven key states: Pennsylvania, Georgia, Nevada, North Carolina, and Arizona, while Harris leads in Michigan and Wisconsin. Polling averages in these swing states mirror these projections.