Freaking Out About the Trump-Clinton Polls? Here’s a Better Way to Read Them.

Ignore the headlines. Find the story being told by the internal data.

how to read a poll.
Take a deep breath and dig deeper into the data.


Early general-election polls have been released, and liberals are freaking out. Donald Trump is almost dead even with Hillary Clinton in the RealClearPolitics average of national surveys, upending assumptions that the race wouldn’t be close. Some Democrats are denouncing the polls as skewed. Others are sinking into panic or fatalism.

Relax. These surveys don’t forecast who’s going to win the election. They tell you how the public feels right now. They show you how different kinds of people are thinking about various questions—how conservative Democrats feel about Clinton, for example, and which qualities women ascribe to Trump. Most important, these polls illustrate how the race might shift, depending on what you and other people do. Here’s a guide to reading them.

1. Don’t whine about party composition. There’s been a lot of bitching on the left about the high percentage of Republicans included in some polls—notably, a Fox News survey taken May 14–17, in which Trump led Clinton 45 percent to 42 percent. In the 2012 election, 38 percent of the people who voted were Democrats; only 32 percent were Republicans. But in the Fox poll, 41 percent of respondents were Republicans; 40 percent were Democrats. That’s typical Fox bias, right?

Wrong. Read the poll’s methodology statement: “The Fox News Poll is not weighted by political party.” That means the poll aims for a random sample, but if more Republicans than Democrats answer the survey (or vice versa), Fox doesn’t tweak its numbers to even things out. (Fox says it does sometime adjust its numbers for imbalances in “age and race,” which can boost one party’s numbers—generally, Democrats.) So if the Fox poll shows a higher percentage of Republicans in May than it did in April—which it does—there’s a chance that the shift has to do with something going on in the electorate, such as rising interest among Republicans. You’d be a fool to close your eyes to that.

If you don’t trust the Fox poll, look at the nearly simultaneous CBS News/New York Times survey. The Times methodology statement says its “sample was adjusted to reflect the percentage of the population residing in mostly Democratic counties [and] mostly Republican counties.” Sure enough, Clinton wins that poll, 47 percent to 41 percent. But if you dig up the detailed tables—not available at nytimes.com or cbsnews.com but posted by the CBS News political team at Scribd—you’ll find something that the Times didn’t report or include in its data sheet. Question 9 of the poll asked: “Compared to past presidential elections, how would you describe your level of enthusiasm about voting in the 2016 presidential election this year—are you more enthusiastic than usual, less enthusiastic, or about the same as usual?” Republicans were evenly split: 36 percent more enthusiastic, 36 percent less. But Democrats were more likely to say their enthusiasm was down (39 percent) than up (30 percent).

That’s a warning. When the Times “adjusts” its sample based on “the percentage of the population residing in mostly Democratic counties,” it’s betting that a partisan enthusiasm gap, such as the one detected in its own survey, won’t significantly change the balance of turnout between Republican and Democratic counties. That “adjustment” is prognostication disguised as polling.

Unweighted surveys avoid that kind of prognostication. This makes them unreliable as election predictors, since they blow in the winds of enthusiasm, which can favor Republicans one month and Democrats the next. But for the same reason, these polls are good at capturing the mood of the moment and at showing how shifts in enthusiasm would affect the election. So instead of whining about the Fox poll, look up the poll’s trend data and check out the correlation between party composition and outcome. Trump has led Clinton in this poll four times: Oct. 10–12, 2015; Nov. 16–19, 2015; Jan. 4–7, 2016; and in May. In each of these samples, Republicans outnumbered Democrats. Every time Democrats outnumbered Republicans in the poll—10 samples in all—Clinton led Trump. The lesson is clear: Solve your enthusiasm problem, get Democrats to the polls, and you win.

2. Notice who’s been sampled. Don’t just look at the number of people polled. Look at who they are. Are they adults, registered voters, or likely voters? A poll of likely voters tells you what might happen if the current distribution of enthusiasm and mobilization doesn’t change. A poll of registered voters tells you what might happen if the current electorate turns out. A poll of adults tells you what could happen if the electorate changes, through registration, and shows up to vote.

Consider the ABC News/Washington Post survey taken May 16–19. The poll shows Trump leading Clinton 46 percent to 44 percent. Those are the numbers reported on RealClearPolitics. But if you examine the data tables, you’ll find that Clinton leads Trump 48 percent to 42 percent among all adults. Register the unregistered, turn them out, and you win. On the Post’s website, you can see how the election changes if unregistered people register. President Obama’s job approval rating goes from negative to positive. Clinton’s net favorable rating, which is even with Trump’s among currently registered voters, surges to a 14-point advantage.

3. Look at trends within each poll. Instead of bickering over whose methodology is better, focus on gaps within the same sample, or on changes within the same poll over time. This kind of analysis cancels out methodological differences. The pattern across the four recent media polls—ABC, CBS, NBC, and Fox—is that Trump has gained ground. In the NBC News/Wall Street Journal poll, Clinton leads Trump by 3 percentage points, but that’s a 10-point drop for her since March. In the ABC/Post poll, her margin over Trump is down 12 points even in the general population.

Scan the Journal’s full data dump, and you’ll see what has changed. Since March, the percentage of Democratic primary voters who said they’d be dissatisfied with Clinton as their nominee has risen from 22 percent to 28 percent. Meanwhile, the percentage of Republican primary voters who said they’d be dissatisfied with Trump as their nominee has fallen from 46 percent to 28 percent. A 24-point gap has vanished.

4. Study favorable ratings. Often, a candidate’s net favorable rating—the percentage of people who view her positively, minus the percentage who view her negatively—is a leading indicator of how she’ll do in the election. In the Clinton-Trump race, these numbers tell three different stories. The first story is that while both candidates have bad ratings, Clinton’s are better than Trump’s. The second story is that Trump has been gaining on Clinton. In the CBS/Times survey, Trump’s net favorable rating has improved by 9 percentage points among independents and by 22 points among Republicans. Meanwhile, Clinton’s net rating hasn’t budged among Democrats and has fallen by 7 points among independents.

But if you step back and look at long-term data, there’s a third story, and it’s more encouraging for Clinton. She has been a national political figure for about 25 years. In the CBS/Times poll, her unfavorable rating, which currently stands at 52 percent, has almost never been this high. It has usually been in the 20s or 30s, with a temporary surge into the low 40s during her previous presidential campaign in 2007 and 2008. Trump’s unfavorable rating, by contrast, has never fallen below 46 percent in that poll. Likewise, while only 34 percent of voters rate Clinton favorably in the NBC/Journal poll, her score on that question has historically stayed above 40 percent, except for a dip in March 2008 and then again in this election. In the ABC/Post poll, Clinton’s favorable rating has been this low only once before, when she was battling Obama for the Democratic presidential nomination in April 2008. By June 2008, her favorable rating had climbed 10 points. The NBC/Journal poll shows a similar bounce during that period. So there’s a case to be made, based on the record, that this is Clinton’s worst moment and that her numbers might recover.

5. Consider candidate attributes. In the ABC/Post poll, Trump narrowly leads Clinton on one issue (“Who do you trust more to handle taxes?”) and one attribute (“Who do you think would do more to bring needed change to Washington?”). On every other issue or attribute on which one candidate beats the other, respondents prefer Clinton. That includes trade, immigration, terrorism, an international crisis, and ethics in government. Respondents say Clinton has better experience, “better understands the problems of people like you,” “better represents your own personal values,” “has more realistic policy proposals,” “would do more to make the country safer and more secure,” and “would do more to advance the economic interests” of the middle class and working class. The CBS/Times poll finds similar results among registered voters. These, too, are often indicators of how people will vote.

6. Consult the national mood. Sixty-five percent of Americans say the country is on the wrong track; only 27 percent say it’s going in the right direction. These numbers have been terrible for more than a decade, under presidents and Congresses of both parties. So which party gets the blame? In the NBC/Journal poll, the Democratic Party’s net favorable rating is negative by 3 percentage points. The Republican Party’s rating is negative by 25 points. The poll also asked: “Putting aside for a moment the question of who each party’s nominee might be, what is your preference for the outcome of this year’s presidential election––that a Democrat be elected president or that a Republican be elected president?” Voters chose a Democrat, 47 percent to 43 percent.

Obama’s approval rating is another index of the national mood. In the CBS/Times poll, he’s at 50 percent positive and 43 percent negative. That’s the first time he has reached 50 percent in that survey in more than three years. In the NBC/Journal poll, his rating stands at 51 percent approval and 46 percent disapproval, up from an 8-point deficit (43 percent approval, 51 percent disapproval) in December.

It’s possible that some of these numbers, which are unusually good for Democrats in the context of the past few years, will revert to a less favorable norm. But if there’s a reversion to the norm in the next five months, it’s just as plausible that what bounces back will be Clinton’s favorable rating rather than the GOP’s.  

7. Find the breakdowns. Most news organizations that sponsor polls don’t routinely show you how particular groups—Republicans, Latinos, seniors, or less educated people, for example—answered each question. Sometimes one sponsor doesn’t show you the breakdowns, but another sponsor does. (Sometimes one doesn’t even give you the data—you have to fish around for the tables behind a paywall somewhere else.)

The ABC/Post poll is exemplary. ABC News gives you a detailed analysis with a full sheet of tables. If you’re a reporter, the ABC News polling team offers further breakdowns on request. The Post’s website also allows readers to mine the data demographically. In this case, the data show that men, by a margin of 27 percentage points, think Trump is a stronger leader than Clinton. Women, by almost the same margin, think the opposite. Men are almost evenly split on which candidate they would trust to handle an international crisis. Women trust Clinton more in that situation, by a ratio of more than 2 to 1. In the Fox poll, men say by a 19-point margin that Clinton isn’t a strong leader. Women, by a 16-point margin, say she is.

So buck up, you nail-biters. Change your undies, take a breath, and learn to read polls for the internal data, not the headlines. Even when the numbers are discouraging, they’re often empowering. They tell you what has shifted, how that’s affecting the election, and what changes would alter the outcome. Maybe you’ll learn to stop arguing with Trump supporters on Twitter  and instead spend your time registering voters in Arizona. You can thank the pollsters later. Even Fox.

Read more Slate coverage of the 2016 campaign.