SIOUX CITY, Iowa ― Sen. Elizabeth Warren is finding friendly faces in unfriendly territory for Democrats on her first trip to Iowa since announcing she will almost certainly challenge President Donald Trump in 2020.

The Massachusetts Democrat on Friday and Saturday spoke to overflow crowds that appeared eager to hear her economic populist pitch and her denunciations of corporate greed and a corrupt Washington.

“Washington keeps working great for people with money, but not for anyone else,” Warren said to a round of applause at a packed theater in Sioux City, promising to “end lobbying as we know it.”

“We need to call it out for what it is: It is corruption, pure and simple. And it needs to stop,” she said.

Although she is the first major candidate to announce a likely bid, Warren’s visit ― complete with a throng of reporters following her, a full complement of staff assisting her, and vendors hawking political merchandise outside the rallies ― seemed to also mark the kickoff to a caucus season that will consume the party for the next year and could see dozens of candidates enter the Democratic fray. Former Housing Secretary Julian Castro is expected to formally announce a bid soon, and other candidates ― including everyone from former Vice President Joe Biden to California Sen. Kamala Harris to South Bend, Ind. Mayor Pete Buttigeg ― could launch campaigns in the coming months.

“This is how it starts. Person to person. Town to town. Across Iowa and then across America,” Warren told a crowd of about 500 in Council Bluffs.

Warren’s itinerary took her through western Iowa, starting in Council Bluffs and Sioux City, two midsize cities on the Missouri River that border Nebraska, before a jaunt to Storm Lake, a meatpacking town with a significant immigrant population. All three locales are in counties Trump won handily in the 2016 election, and Storm Lake and Sioux City are in the congressional district of notorious GOP Rep. Steve King.

In Sioux City, she grounded her pitch in her own family’s life story, relating how they almost fell into poverty when her father had a heart attack in middle age and her mother feared losing their house, which was saved when her mom got a minimum wage job.

“Today, a minimum wage job in America, full time, will not keep a mama and a baby out of poverty,” she said, arguing the fight for the middle class has been her life’s work as a teacher, professor and U.S. senator. “And it is wrong, and that’s why I’m in this fight.”

She also boasted about her work creating the Consumer Financial Protection Bureau, her defeat of GOP Sen. Scott Brown in 2012, and legislation she passed that will drastically lower the cost of hearing aids.

ASSOCIATED PRESS Sen. Elizabeth Warren (D-Mass.) speaks at McCoy's Bar Patio and Grill in Council Bluffs, Iowa, on Jan. 4.

Warren’s travels continued with an event Saturday night in the state capital of Des Moines that drew more than 1,000 people. On Sunday, she’ll meet with a group of female leaders in the rapidly growing suburb of Ankeny. The trip is her first to Iowa since 2014, when she campaigned for former Rep. Bruce Braley in Iowa’s Senate race.

The events were not without hiccups ― Warren’s mic cut out for five minutes during her Council Bluffs event, a Trump supporter was arrested outside the Storm Lake event for striking a person with a selfie stick, and the candidate was beginning to lose her voice by midday Saturday. But the toughest moment for Warren came when a voter questioned her about her decision to get a DNA test to prove her Native American ancestry.

“Why did you undergo the DNA testing and give Donald Trump more fodder to be a bully?” a woman asked.

“I am not a person of color,” Warren responded. “I am not a citizen of a tribe. Tribal citizenship is very different from ancestry. Tribes ― and only tribes ― determine tribal citizenship, and I respect that difference.”

She then shifted back to her core message: “What I can do is I can be in this fight for all of our families. What I think 2020 is going to be about is not my family, it’s about the tens of millions of families across this country who just want a level playing field.”

Trump has signaled he has no plans to stop his attacks on Warren’s heritage. This week, he tweeted out a fake bumper sticker mocking the senator. For the most part, Warren avoided direct attacks on the president – she never mentions him by name in her stump speech.

With the pivotal caucuses still more than a year away, Warren is the first major candidate to travel to the Hawkeye State. Dozens of candidates, including many of Warren’s fellow senators, are likely to enter the contest. Early opinion polls of Iowa place Warren in the mix, but position Biden and Vermont Sen. Bernie Sanders as the Democratic front-runners. Warren is expected to draw support from both former backers of Sanders and voters who backed eventual nominee Hillary Clinton in 2016.

In her appearances throughout the state, there were also hints of how she would differentiate herself from Sanders, who could be her main rival for the votes of progressives. While the Vermonter almost never mentions his own life experiences on the trail, Warren dwelled heavily on her own biography: She rued her decision to drop out of college at age 19 to get married and referenced her efforts to potty-train her 2-year-old daughter and her time as a fifth-grade Sunday school teacher.

And while Sanders’ biggest applause lines typically come when he mentions one of his signature policy pushes ― expanding Medicare for people over the age of 65 to the entire American population ― Warren avoided directly mentioning the issue, instead repeatedly discussing the importance of Medicaid. Warren has co-sponsored “Medicare for All” legislation in the Senate.

“No one’s raised it,” Warren told reporters in Sioux City when asked why she hadn’t mentioned the plan. “But I have had a chance to talk about Medicaid. We’ve had a national conversation about health care, and I think it’s been enormously valuable.”

Still, few people at any of the events were ready to commit to vote for Warren a year from now, with many hoping to hear from former Texas Rep. Beto O’Rourke, Harris or other candidates.

Tim Daugherty, a post office worker from Council Bluffs, said he thought Iowa voters would appreciate Warren’s fighting spirit.

“She’s not afraid to stand toe to toe with Trump,” he said.

Woodbury County Democratic Party Chair Jeremy Dumkrieger, who attended the Sioux City event, said he was pleased Warren started out in western Iowa.

“It shows all of us that she understands Iowa is a lot more than just Des Moines,” he said. And he anticipated voters would be ready for Warren’s message. “After a couple of years of Trump, we’re ready to just say what we believe.”

This story has been updated with additional details.