Political pollsters usually don't tell you about these people: the Americans who aren't planning to vote.
Yet in a close election like this year's presidential race, those who aren't currently planning to vote could matter a lot, if the campaigns can move them from the sidelines to polling places. The latest Bloomberg Politics national poll shows that Hillary Clinton has more of a stake in trying to motivate them than Donald Trump.
The Bloomberg survey for the first time asked unlikely voters who they would back, if they had a change of heart and decided to cast a ballot. What it showed is greater support for Clinton than Trump among those not likely to vote, as well as a non-voter profile that skews Democratic.
The findings show that those not planning to vote back Clinton over Trump, 38 percent to 27 percent, if they did indeed cast a ballot. That 11-point difference, although subject to a margin of error of plus or minus 5.5 percentage points, helps underscore the importance of turnout for the Clinton campaign.
Democrats from President Barack Obama on down are worried about voter apathy among non-whites, so much so that he told one recent audience that he would consider it a "personal insult" if black voters didn't back Clinton.
Polls, including Bloomberg's, have also shown young voters are also a problem for Clinton. Those under age 35 are more likely to be non-voters than likely voters, 54 percent to 46 percent, the poll showed.
As a way to try to address the problem, Clinton's campaign has increasingly started to tailor campaign events to younger votes. She appeared Wednesday in New Hampshire with Bernie Sanders, her primary rival, at an event that focused on college student debt and her proposal for free college tuition for families earning less than $125,000.
Clinton's campaign said Wednesday that it's trying to arrange more events with Sanders because he has a strong appeal to millennial voters and those thinking about supporting third-party candidates because of his independent affiliation as senator from Vermont. "He's a particularly powerful voice on that front," Jennifer Palmieri, Clinton's communications director, told reporters.
In October, Clinton's campaign is expected to focus more heavily on get-out-the-vote efforts, especially in battleground states where early voting will be underway. Trump's turnout efforts, heavily dependent on the Republican National Committee, will also be growing in intensity.
At this point in the campaign, pollsters typically screen for respondents they deem likely to vote. How they define that differs, sometimes markedly, from pollster to pollster.
Selzer & Co., the Iowa-based firm that oversaw the Bloomberg survey, asks those who answer the phone whether they have already voted, will definitely vote, probably vote, might or might not vote or probably not vote. Just those who say they have already voted or will definitely vote are included as likely voters.
The survey also shows Clinton has upside potential, if she can convince more non-whites to vote.
Among non-whites, 52 percent are likely voters in the poll, while 48 percent were non-voters. For whites, a group key to Trump's success, 74 percent of those contacted were likely voters, while 26 percent were classified as non-voters.
The poll was taken Sept. 21-24 and included 1,002 likely voters and 324 respondents not classified as likely voters.
—With assistance from Margaret Talev in New Hampshire.