The poll from The Associated Press-NORC Center for Public Affairs Research and MTV found that just 33 percent of Americans between the ages of 15 and 34 approve of Trump's job performance.
That's 9 points lower than all adults, who were asked the same question on a separate AP-NORC survey taken this month.
"Trump doesn't care about us," said 27-year-old Nicole Martin, an African-American graduate student in Missoula, Montana. "I'm not going to say he's unfit like he has schizophrenia. I do kind of think he's twisted in the head. He just comes off as disgusting to me."
The survey is the first in a series of polls designed to highlight the voices of the youngest generation of voters. The respondents, all of whom will be old enough to vote when Trump seeks re-election in 2020, represent the most diverse generation in American history.
They would occupy the largest share of the electorate — if they vote at the same rate as older Americans. But history suggests they are also the least likely to vote this fall. In the 2014 midterm elections, for example, only about 20 percent of 18-29 year-olds cast ballots.
Asked if she will vote this fall, when the president's party, but not the president himself, will be on the ballot, Martin said: "I haven't really thought about it."
Still, there are signs that seven months before the midterm elections, young people appear to be more engaged in politics. Nearly half of younger Americans, 47 percent, say they're personally paying closer attention to politics since Trump's election; 2 in 10 say they're engaging in political activism more than before.
High school students led massive protests nationwide last weekend that called for gun control in the wake of the recent school shooting in Parkland, Florida, that left 17 dead, and the poll found that young people are more focused about guns than any other issue. Twenty-one percent say the nation's gun laws are their top concern, while 15 percent cited the economy and 8 percent said social inequality.
There is widespread agreement among young people about Trump, with more than 7 in 10 saying he "doesn't reflect my personal values."
"He doesn't seem to be really for women. He doesn't seem to be for Black Lives Matter. He doesn't seem to be for DACA," said Meghan Carnes, 23, of New York City, referring to a program to allow young immigrants to stay in this country. "He doesn't seem to be for the kids worried about guns. It's extremely disappointing to have a president who doesn't seem to care."
The new poll finds that 60 percent describe Trump as "mentally unfit," 62 percent call him "generally dishonest," and 63 percent say he "is a racist." In a mid-February AP-NORC poll, 57 percent of all adults in the U.S. said they believe Trump is racist.
Spencer Buettgenbach, 23, of Topeka, Kansas, said the Republican president has emboldened attitudes about racism, sexism and homophobia by "normalizing abusive talk."
"Especially living in Kansas — for me as a gay man — it's kind of scary," he said. "He's like the world's worst boogeyman."
The poll also found that young people overwhelmingly support watching out for minorities: 69 percent favor a pathway to legal status for immigrants brought to the country illegally as children, 59 percent favor protecting the rights of LGBT citizens, and 58 percent say the same for Muslims.
Among other issues young voters feel the strongest about:
— 76 percent want the government to allow them to refinance student loan debt at lower rates
— 67 percent want a health care system in which "the government provides health insurance to all Americans."
— 60 percent want the government to take steps to address climate change.
A narrow majority, 55 percent, favor legalizing the recreational use of marijuana. Just under half, 46 percent, believe abortion should be legal "in most cases," with 26 percent opposed.
Trump's domestic priorities are far less popular among young people. Only 22 percent favor the Republican-backed tax overhaul, while 40 percent are opposed. More than half oppose construction of a wall along the Mexican border to curb illegal immigration. Thirty-six percent want to increase defense and military spending, though just 27 percent say they're opposed.
Kristopher Cochran, 22, a conservative who voted for Trump, said he's "neutral" about the president's job performance so far. He suggested Trump is being treated unfairly by the media — an opinion shared by 54 percent of young Americans.
Cochran, a mechanical engineering student at Virginia Tech, dismissed concerns about Trump's mental fitness.
"If he was mentally unfit, I don't think he would have made as much money as he did, but I can see why people would think that," he said. "I'm not a fan of his incessant need for Twitter. He acts like a child."
Cochran is not alone in his strong feelings about the president's use of social media. Asked how they would advise Trump on Twitter, 49 percent said they'd tell him to "delete your account" and 37 percent said "take it down a notch."
Just 13 percent said, "Keep doing what you're doing."
The Youth Political Pulse poll of 1,027 young Americans age 15-34 was conducted Feb. 22 to March 9 by the AP-NORC Center and MTV. The poll was conducted using NORC's probability-based AmeriSpeak panel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 4.2 percentage points.