DES MOINES — They are angry at a political system they see as rigged. They feel squeezed by immigration, or the power of big banks. They sense that America is heading in the wrong direction, but emphatically believe only their candidate has the strength and vision to change things.
The voters driving two of the more remarkable movements of this election cycle — for Donald J. Trump and SenatorBernie Sanders — share striking similarities. Both groups are heavily white, more male than female, and both are fueled partly by people who, in interviews, express distrust of their parties and the other candidates, especially Hillary Clinton.
No matter how their preferred candidates fare in the Iowa caucuses on Monday, the supporters of Mr. Sanders and Mr. Trump are reshaping the campaign and could have a profound impact on the outcome in the fall.
In dozens of interviews at rallies in Iowa, and longer conversations in their homes or workplaces, supporters of both candidates spoke openly of their anxiety about the future. Even if they were not personally affected by the economic downturn, Mr. Sanders’s supporters worried about the growing inequality in wealth and income; Mr. Trump’s worried about terrorists coming across the border.
Yet there was also palpable enthusiasm for their candidate and hopefulness about the future he represented. They believe that only their candidate can fix a broken system because he is not beholden to it; neither has a “super PAC” for big donors to pour money into.
Many in both groups said they had never felt so strongly about a political figure before.
“He stands for everything I believe in,” said Alex Curtis, 19, who traveled six hours from Nebraska to hear Mr. Sanders speak last Sunday in Fayette, Iowa. “He’s going to restore the American dream and bring class mobility.”
Said Toby Richards, 50, a farmer from Knoxville, Iowa: “It’s so refreshing to have someone who’s not being bought, and Trump’s not being bought. What he says now can’t be swayed by money.”
The two movements have significant differences: Mr. Trump attracts support across a wide spectrum of demographic groups, but is strongest among Americans without a college degree (eight of 10 Trump supporters do not have one) and those with lower incomes, according to a New York Times/CBS News poll in December.
Mr. Sanders draws strong backing from younger voters and self-identified liberals, and 43 percent of Sanders backers are at least college graduates, the same survey showed.
“They’re younger, they’re proud of being liberals, and they like Senator Sanders personally,” said Peter A. Brown, assistant director of the Quinnipiac University Poll.
Trump and Sanders voters are the likeliest among their parties to be “angry” at Washington, according to the Times/CBS News poll, with 52 percent of Trump backers and 30 percent of Sanders backers identifying that way.
Anger has risen steadily since 2010 among both Democrats and Republicans, according to polling conducted by The Times and CBS News. Republicans are more likely than Democrats to say they are angry, and whites are more likely than African-Americans to say they are angry. But the rates for all are going up, and their anger appears to be one factor sweeping Mr. Trump and Mr. Sanders from the relative margins to the top of many polls.
In interviews with voters in Iowa, the anger simmered close to the surface. “Oh, heck, yeah, I’m angry,” said Savannah Granahan, 52, who plans to caucus for Mr. Sanders and attended a campaign event for the first time this month, near her home in Fort Dodge. “This country isn’t run by the government. It’s run by the almighty dollar.”
About 85 miles away, Esther Toney, 71, a retired prison guard from Collins, returned from a Trump rally in Ames fired up. “Oh, I’m very angry,” said Ms. Toney, who comes from a family of Democrats. “I’m extremely angry. We’ve got politicians that are just there for their own gain. They should be thinking about how they can make our lives better. And they don’t. They vote on things to support their PACs or whoever gave them money.”
The targets of their anger diverge. Mr. Trump’s supporters directed their wrath toward career politicians, unlawful immigrants, terrorists and people who they said were taking advantage of welfare. Mr. Sanders’s supporters assailed big banks and economic inequality.
Mr. Sanders’s supporters tended to blame the campaign finance system for Washington dysfunction; Mr. Trump’s supporters blamed the politicians who they said cared only about donations.
“Look at our health care,” said Sean Bolton, 42, of Norwalk, a Trump supporter who once voted for Barack Obama because of similar promises of independence. “Who do you think wrote those laws? I guarantee it was the insurance companies and drug manufacturers of the world.”
And while people in both groups express criticism of Mrs. Clinton, it is for different reasons: Supporters of Mr. Sanders find her dishonest; fans of Mr. Trump worry she would continue the policies of President Obama, which they oppose.
Both camps include many people who have not been active in the Iowa caucuses before, or previously supported the other party. And the characteristics they bring up in describing their chosen candidate are distinct: Those in Mr. Trump’s camp said he would bring better financial and negotiating skills; those in Mr. Sanders’s said he would bring better conditions for average working people.