WASHINGTON — (CNN) Hillary Clinton tops Donald Trump in two new polls of younger voters, but both surveys suggest that many young voters are inclined to choose someone other than the two major party candidates or to stay home entirely on election day.

Dissatisfaction with politics and with the choices on this year’s ballot are widespread among millennial voters.

That could be troubling news for Clinton’s campaign, despite her overall lead in the group.

That voters under age 30 tend to lean Democratic isn’t a shock — the group hasn’t backed a Republican for president since 1988, according to network exit polls — but their turnout and strength of support for the Democrat can sway the outcome.

Neither poll suggests Clinton holds the backing of a majority of younger voters.

The Harvard IOP poll finds Clinton topping Trump by a 45%-to-23% margin among those most likely to vote in the fall, with 13% behind Libertarian candidate Gary Johnson and another 19% unsure who they’d support.

And the GenForward Survey, which interviewed the broader group of adults age 30 and younger and did not include Johnson in the list of candidates, found Clinton ahead by a similar margin, holding 38% to Trump’s 17%, with 22% backing someone else, 7% undecided and 16% saying they probably wouldn’t vote at all.

In almost every election since 1988, younger voters have favored the Democrat over the Republican by a margin of 9 points or more.

The exception was 2000, when Democrats’ advantage among younger voters shrank, with Al Gore narrowly topping George W. Bush among voters under 30 by just 2 points.

Younger voters were a key component of Barack Obama’s winning coalition in 2008, and while they generally broke in Obama’s favor again in 2012, Obama lost ground among younger whites, dampening his margin among the under-30 voter set.

The GenForward study, from the Black Youth Project at the University of Chicago with the AP-NORC Center for Public Affairs Research, drilled down into racial and ethnic divisions among younger voters, finding Trump’s support among black, Asian and Hispanic youth in the single digits, while he carries about a quarter of younger white voters.

Black and Hispanic youth who back Clinton are far more likely to describe their vote as one of support for the former Secretary of State, while white and Asian young adults who favor her mostly say they are expressing opposition to Trump.

The Harvard IOP Poll echoes that sentiment, with just 21% of Clinton’s backers saying they’re very enthusiastic about supporting her, while 36% of Trump’s backers say the same.

In both polls, majorities express unfavorable views of Clinton and Trump, but the GenForward study suggests they have more faith in Clinton’s qualifications for president — 55% see Clinton as qualified compared with just 21% who say Trump is.

This week also featured a survey sponsored by Fusion which asked those age 35 or younger to describe a Trump presidency in one word, and found far more negative responses than positive ones: 70% used a negative word or phrase, with variations on “scary,” “horror” and “terrified” topping the list.

Perceptions of both Trump and Clinton pale in comparison among young voters to those of a candidate who is no longer in the race: Bernie Sanders.

More than 7 in 10 in the GenForward study call him qualified, and if he had been the Democrat on the ticket in November, more than 6 in 10 say they would’ve voted for him over Trump.

In the Harvard IOP survey, 54% expressed favorable views of the senator from Vermont.

Given their current choices, however, 7 in 10 young adults say they would like for a third-party candidate to run, according to the GenForward survey, while just 3 in 10 say they are satisfied with the choice of Clinton or Trump.

That dissatisfaction extends to the political system generally.

A third or more in both polls thought the political system needed major work, with 36% in the GenForward poll saying “the two-party system is seriously broken” and 33% in the Harvard IOP survey saying politics needed “to find a reset button and start again.”

Few major polls have extensive samples of younger voters, as they are typically harder to reach by telephone than older Americans.

Two of these polls were conducted online, using panels that were recruited by traditional mail or telephone surveys, one was conducted by phone.

The GenForward Survey was conducted online June 14-27 among 1,965 adults age 18-30. Results have a margin of sampling error of plus or minus 3.8 percentage points.

The Harvard Institute of Politics Poll was conducted online June 21-July 3 among 1,001 18-29 year olds, and has an error margin of plus or minus 3.5 percentage points.

The Fusion Poll was conducted by telephone by Langer Research Associates June 1-14 among 983 adults age 18 to 35.