Vermont Sen. Bernie Sanders, who is vying for the Democratic presidential nomination, was a guest on ABC's "This Week" on Sunday and mentioned his chief rival for the party's nomination, Hillary Rodham Clinton.

One year before the presidential election, a pervasive disquiet has shaped voter attitudes, with a majority of Republicans pessimistic about moral values and the increasing diversity of the country's population, and Democrats uneasy about an economy they see as tilted toward the rich.

By more than 2 to 1, voters both nationally and in California say they are more worried than hopeful about changes in the country's morals and values. By nearly the same margin, more worry than express hope about the changing national economy. And by 5 to 1, they say they are worried about how the nation's politics have changed.

California voters and those nationwide largely agree on those points but diverge on others. Nationally, for example, voters divide almost evenly on whether cultural diversity worries them or makes them hopeful. In California, those who are "mainly hopeful" about the changes caused by cultural diversity outnumber those "mainly worried" 56% to 41%.

Those concerns -- detailed in a new USC Dornsife/Los Angeles Times poll, conducted online by SurveyMonkey -- have been driving voter decisions about which candidates they favor for president. In California and nationwide, they have helped propel two nontraditional candidates, businessman Donald Trump and retired neurosurgeon Ben Carson, to the forefront of the Republican field.

Trump tops the field nationally, but barely, the poll found. He has support of 25% of registered Republican voters to Carson's 21%. Statewide, the two are essentially even, with Trump at 20% and Carson at 19%.

Maybe Larry David should run for president.

After all the agony and ecstasy, the promos and protests, Donald Trump may have hosted “Saturday Night Live,� but David owned it, first reprising his scary-great Bernie Sanders in the show’s opening skit and then giving voice, literally, to the hundreds gathered outside the NBC studio at 30 Rockefeller Center.

“You’re a racist,� a voice yelled as Trump mugged with Taran Killam and Darrell Hammond, both in Trump drag. “Trump’s a racist,� David shouted as the camera panned his way. “What are you doing, Larry?� Trump asked.

“I heard if I yelled that, I’d get $5,000,� David said with his signature joking-not-joking smirk, referring to DeportRacism.com's offer.

“As a businessman, I can respect that,� Trump quipped in what was clearly intended as the bit’s punchline. But it was too late. Trump had been upstaged by the best of them. Later in the show, he may have “chosen� to live-tweet a sketch rather than participate in it, but it was David who immediately blew up on Twitter.

Ben Carson offered a strong defense of his biographical anecdotes Sunday after days of questions about the accuracy of his descriptions, and accused the media of trying to derail his campaign by sowing doubts about his truthfulness.

Speaking on CBS’ “Face the Nation,� Carson, who is polling toward the top of the crowded GOP presidential field, said his campaign is receiving “special scrutiny� at a time when he has momentum three months before voters begin casting ballots.

“I'm getting special scrutiny. Because, you know, there are a lot of people very threatened … they're worried. There is no question about it,� said Carson. “And, you know, every single day, every other day or every week, you know, they're going to come out with, 'Well, you said this when you were 13.' And the whole point is to distract the populace, distract me. You know, if you've got a real scandal, if you've got something that's really important, let's talk about that.�

On Friday, a report in Politico questioned Carson’s assertion in his autobiography, “Gifted Hands,� that he had been “offered a full scholarship to West Point.� The military academy does not offer scholarships because tuition is free for those accepted. Carson was not admitted to West Point, but graduated from Yale.

“Well, you notice I said it was offered. I didn't say I received it,� Carson said Sunday on “Face the Nation.�

“You know, I was in the process of some kind of banquet, there were a lot of military officials there. They were very impressed with my incredible rise to city executive officer faster than anyone had ever done that before,� he said. One or more people at the banquet, Carson did not specify who, “said that, you know, ‘Well, we would be able to get you a full scholarship to West Point.’ And I said, ‘That's wonderful.’�

Barry Bennett, Carson’s campaign manager told the Los Angeles Times on Friday that while the wording Carson used to describe his offer from West Point in the book was not ideal, it was not inaccurate.

“I would not have used the word ‘full scholarship.’ I would have said ‘nomination,’ but it’s not a fabrication, it’s not a lie,� he said.

The Wall Street Journal on Saturday questioned another aspect of Carson’s autobiography, his description of a psychology course he said he took while at Yale. Carson wrote that he took a class called Perceptions 301 and that an experiment run in the class found him to be the most honest student there. The Journal quoted Yale officials who said there was no such course offered at the university at the time he was a student.

“It will be coming out, you know, in the next day or two, showing what happened with that psychology course. Why could we find it and they could not find it? And why do people put this stuff out there to make the accusation to try to make somebody seem dishonest?� Carson said on Sunday.

Other elements of Carson’s background, including his tales of a violent upbringing in Detroit, have also been called into question in recent days.

Carson’s biographical anecdotes are part of a life story that, along with his Christian faith and status as a political outsider, have boosted his poll numbers. A USC Dornsife/Los Angeles Times poll released this weekend showed Carson in second place nationwide among Republican voters, at 21%, just behind billionaire businessman Donald Trump, who had the support of 25%.

Ahead of Tuesday night's FOX Business/Wall Street Journal presidential debate, stay up-to-date on the candidates and their backgrounds.

In a change from previous debates, New Jersey Gov. Chris Christie and former Arkansas Gov. Mike Huckabee will not be on the main debate stage, but instead will be a part of the undercard debate because of poor polling numbers.