The results of the 2024 presidential election cement a trend in American politics: Polls cannot accurately gauge support for Donald Trump. In the 2016, 2020 and now 2024 elections, polls consistently underestimated Trump's support by an average of 2.3 percentage points. While that average polling error is within the standard margin of error for most polls—typically plus or minus 3 percentage points—the real explanation is not that simple.