How do they know how we voted?

If ballots are anonymous, how is demographic information about voters obtained? The answer: Exit polls.

A chart showing the purported demographic breakdown of votes cast in the 2024 U.S. presidential election. The data were collected from exit polls conducted by Edison Research and published by NBC News. This image is a screenshot. You can find more detailed polling results here.

Now that the 2024 U.S. presidential election is over - and former President Donald Trump has won - the blaming and score-settling on the losing side is in full swing.

High on the list of Democrats' ire are the groups of voters who traditionally have voted blue but apparently 'swung red' for this election.

According to the Associated Press:

Trump picked up a small but significant share of Black and Hispanic voters, and made narrow gains with men and women. As Trump chipped away at parts of the Democratic coalition, Vice President Kamala Harris wasn’t able to make enough of her own gains. Trump succeeded in locking down his traditionally older, white base of voters, and he slightly expanded his margins with other groups into a winning coalition.

But, if how you vote is truly private and anonymous - and it is - how does the AP (and everyone else) know the gender, age, and ethnic background of how people voted?

The answer is exit polls.

No one actually has access to the demographic information for all voters. They ask a subset of voters from a predetermined mix of precincts and groups of voters and extrapolate those results to the entire voting population.

This is not the exact science that many news stories make it out to be.

According to Time magazine:

Exit polls tend to overrepresent the kinds of people who are likely to stop and agree to talk to a pollster, and underrepresent the ones who don’t. They’re also conducted on the fly, attempting to snapshot the electorate in real time, so they’re naturally not going to be as accurate as an analysis that combs through voter files and other data that show who actually turned out. (Ironically, the thing the exits are worst for—determining the demographic breakdown of the electorate—is the thing they’re most often cited to illustrate.)

Remember that oft-cited statistic from 2016 that 52 percent of white women voted for Trump?

As a white woman and lifelong Democrat, then living in a deep blue dot in a deep red state--I certainly do.

Later, more careful analyses have corrected many of the exits’ snap judgments, busting many myths about the election along the way.

The 52% statistic appears to be one of those myths. According to a later analysis that experts consider more reliable, a study published in August by the Pew Research Center, the percentage of white women who voted for Trump was actually 47%, compared to 45% for Clinton. That’s still a plurality, and still makes white women more Trump-positive than the overall electorate, which supported Clinton by a 48%-46% margin. White women ... were considerably more pro-Trump than nonwhite women, who went for Clinton by a huge margin, 82%-16%. But it’s essentially a tie, which makes for a very different story than a 9-point margin for Trump.

While demographic voting trends are useful for campaigns, the way the results are reported and consumed tends to lead to bitter divisions among voters and communities as people try to figure out who among the people they know personally are the 'one out of every two,' or 'one out of every four' of whatever type of person, who's to blame.

Just like election predictions, early primaries, and routine polling--I think this can have psychological effects on people and even affect how they vote.

Everyone is susceptible--in different degrees--to wanting to fit in with peers. If they feel they are an outlier, they may feel isolated and defensive--or they may change their vote, or even not vote, based on speculative and sometimes erroneous information.

The election is over. It is clear who won. Assigning blame can feel cathartic, but is rarely useful. And, with this kind of polling, may be outright wrong.

We need to move past the blame game and look toward the future.

More About It

What are exit polls and how are they conducted? Below are some of the articles I read when researching this post. Check them out to see how exit polls are designed and how each polling group gets their information.