For some voters, reacting to President Trump is precisely the problem. They say the president has made it so that Democrats devote their speaking time and mental energy to decrying him, rather than articulating their own policy positions.

Isaac Barron, a high school teacher and city councilman in North Las Vegas, a suburb with a large Latino population, has watched nearly every candidate come through his neighborhood in the last several months. They try, he said, to appeal to communities like his own, but there is always something missing, absent a mix of urgency and passion when it comes to talking about the problems they’re facing.

“It just goes to show you that it might be 2020, but things haven’t changed,” Mr. Barron said, adding that in many ways he feels the conversation about racial injustices has lost a sharp focus in recent years. “There’s a real lack of understanding. Poverty is a huge issue, but we’re not talking about it. We care about immigration, yes — I’ve lost track of the number of students who come to me with tears in their eyes because their father got arrested by ICE. But we still have difficulty getting beyond the basics.”

Steven Olmos, a 34-year-old operations manager, initially supported Senator Kamala Harris, but worried that as a black woman she would face too many insurmountable challenges, including being seen as too forceful.

“Right now, they are being careful not to offend anyone, not to take on topics that are too hot and will alienate people,” he said, as he stood outside a rally for Mr. Buttigieg in North Las Vegas on Sunday, holding a “Juntos con Pete” sign.