Millennials’ interest in Libertarian nominee Gary Johnson is keeping the presidential race between Hillary Clinton and Donald Trump close, House Minority Leader Nancy Pelosi said Tuesday, and it’s up to Clinton to win them over.

The California congresswoman said Democrats will make gains in the House in November, the San Francisco Chronicle reported. But most experts believe it would take a Clinton landslide for the party to win the 30 seats necessary to take control.

Clinton took a large lead in national polls and in battleground states after the party conventions this summer, but most polls now show the race within a few points.

Young voters fueled Vermont Sen. Bernie Sanders’ candidacy in the Democratic primaries, but they haven’t fallen behind Clinton in the race against Trump.

Voters across the board have trust and honesty issues with both Clinton and Trump, but their unfavorable numbers are highest among younger age groups and Johnson polls higher among those groups.

[Generation Gap: Can Clinton and Trump Reach Millennials?]

Sanders will work hard for Clinton in these remaining weeks of the campaign, Pelosi said, but Clinton, “is going to have to make her own case to them as well because you can only transfer so much.”

Prospects for House Republicans are improving with Trump’s numbers, House Majority Leader Kevin McCarthy said Monday.

“As (Trump’s) numbers go up, our numbers go up as well,” the California Republican said.