Susan Page and Karina Shedrofsky

USA TODAY

WASHINGTON — Millennials back Hillary Clinton over Donald Trump by more than 3-1, a new USA TODAY/Rock the Vote Poll finds, but enthusiasm about voting is dipping as a sharply negative campaign enters its final weeks.

The impact of the invective and attacks that have defined the 2016 race is apparent among the nation's largest and rising generation. Among Americans under 35, Trump supporters say that their main reason by far for backing him is to keep Clinton out of the White House. Clinton supporters in equal numbers say their main reason for backing her is to keep Trump out of the White House.

"I am very afraid for our country," says Richard Devine, 20, a freelance media producer from Bath, in upstate New York, who was among those polled. He plans to vote for Clinton, but without the excitement he felt for Vermont Sen. Bernie Sanders during the Democratic primaries. "Hillary (has) a lot of scandals on her back," he says, but he views her opponent as worse. "Trump is a horrible person," he says.

The campaign has been "really annoying," says Natalie Harris, 29, an occupational therapist from Melbourne, Fla., and a Trump supporter. "It's kind of like fighting with your brother or sister, but dirtier."

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Enthusiasm about the election peaked in the March poll, when Sanders was drawing wide Millennial support in his bid for the Democratic nomination. It dropped in August and dipped a bit more this month. The online survey of 1,020 adults 18 to 34 years old, taken by Ipsos Public Affairs Oct. 11-13, has a credibility interval (akin to a margin of error) of plus or minus 3.5 percentage points.

Those who are likely voters overwhelmingly support Clinton, 68%-20%, as Trump's support hits historic lows and backing for third-party candidate ebbs. But concern among Democratic strategists about whether voters under 35 can be counted on to show up and vote is prompting candidate speeches and surrogate appearances targeting them. "We cannot afford to be tired or turned off," first lady Michelle Obama warned a rally at Southern New Hampshire University last week. "And we cannot afford to stay home on Election Day."

That is a risk in the age group that typically is the least likely to vote and this year has lost much of the energy that fueled support for Sanders. In January, 55% agreed with the statement, "There are better ways to make a difference than voting." Now 62% endorse that sentiment. At the beginning of the year, 37% said, "My vote doesn't really matter." Now 46% feel that way.

That said, eight in 10 call voting a responsibility and say it is a way to have an impact on issues they care about.

Among those who are undecided or don't plan to vote, two-thirds say the reason isn't because voting doesn't matter or because they're not interested in politics. Instead, they say it is because "I don't like any of the candidates."

Setting a record

If Clinton has a problem generating enthusiasm among Millennials, Trump faces outright rejection. He trails Clinton by a stunning 48 percentage points among likely voters. Even a third of Republican Millennials don't back him.

His support among younger voters is now significantly lower than that of any major-party presidential candidate in modern times. He trails even Robert Dole, who hit the low-water mark of 30% in a three-way race against Bill Clinton and Ross Perot in 1996.

Kristiana Kershaw, a student at Loyola University in Chicago, plans to vote for Trump because she likes his business expertise and his conservative policies. But she keeps quiet about it. "My only concern is that as an 18-year-old supporting Trump, I can't say that I support him because it's not safe for me to say that," she says. "On a college campus, people feel very strongly and social-media bias says Hillary is the only candidate."

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The first two presidential debates hurt Trump among Millennials. A majority of those surveyed say the debates made him seem less presidential, less credible and less trustworthy. By wide margins, they made him seem less accessible and less "human."

The debates generally helped Clinton. Forty percent say she seemed more presidential, compared to 24% who say she seemed less presidential. By a margin of 15 points, the debates made her seem more rather than less "human."

But the debates didn't boost the former secretary of State when it came to seeming trustworthy and credible.

In a disparity that has frustrated her campaign, younger women remain significantly less likely than their male counterparts to support Clinton. Two-thirds of men, 65%, plan to vote for her. Despite her breakthrough status as the first woman nominated by a major party for the presidency, just 47% of women support her.

Indeed, men are more likely than women to cite the fact that Clinton is a "groundbreaking candidate" as a major reason for backing her, 11% to 7%.

That doesn't mean Millennial women are drawn to Trump. Just 18% support the GOP nominee, a bit lower than his 20% support among men. But an equal 18% of women support Libertarian Gary Johnson or Jill Stein of the Green Party. Just 6% of younger men are backing those third-party candidates.

"I'd love to see a female in the office," says Mara Jones, 31, a nurse from Mesquite, Texas. But she plans to vote for Stein, not Clinton. "I can't see myself voting for Hillary just to keep Trump out of office; can't vote for Trump because of things he's said," she says. She is determined not to "just vote the lesser of two evils."

Is it Trump or Clinton?

2016 Poll Tracker - USA TODAY

Still feeling the Bern

Sanders still looms as a powerful factor for Millennials. A majority of those surveyed say they supported the Vermont senator during the primaries. Clinton has consolidated support among most but not all of them: Eight in 10 of former Sanders supporters back her; one in 10 support Trump. Six percent plan to vote for Johnson or Stein.

Sanders "seems a little bit more real than all the candidates," says Susan Miller, 34, a researcher from Allentown, Pa., a former Sanders supporter who is trying to decide between voting for Johnson or Clinton. "Where he was coming from was a more human approach than narcissistic and political."

Among all Clinton supporters, 36% say their main reason for backing her is to block Trump. The only other reason cited by double digits is that she has "the right experience to lead," chosen by 16%.

Among Trump supporters, an equal 36% say their main reason for backing him is to block Clinton. The only other reason cited by double digits are the 17% who say he is "best suited to fix America."

The downbeat mood of Millennials today contrasts with the generation's optimism in 2008, when Barack Obama's message of hope and change drew the support of 66% of voters under 30, the highest level in modern times.

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Now, there is broad agreement among Millennials about what the top priority should be for the next president: Jobs and the economy, cited by nearly four in 10. "Trump has a point when he talks about all of our jobs going elsewhere," Kershaw says. Next on the list of top concerns are health care, college affordability, civil rights and foreign policy/terrorism.

"Terrorism and the safety of our country is probably the top priority, and the economy — just getting our country in a good place," says Kimberly Steenblick, 32, a homemaker from Sacramento who is undecided. "I have kids, so I want whoever is president to do whatever they can to make sure when my kids are older that the world they live in is just as safe and enjoyable as it has been."

She'd like to see the next president "bring unity into the country," but she is skeptical that's going to happen. "I feel like whoever wins this year, the opposite side will just complain about everything they do," she says.

"I don't honestly think the politicians can come together," says Emily Bennett, 34, a dog-sitter from Bloomer, Wis., who leans toward Clinton but isn't sure whether she'll bother to vote. "It doesn't matter who is in office. They never seem to agree on anything or get anything done."