DES MOINES — Fresh off his presidential announcement in Baltimore, Martin O’Malley arrived Saturday afternoon in Iowa, where he was warmly received but also faced questions about his place in a Democratic field that already includes a heavy favorite and a liberal alternative.

In his first campaign appearance since becoming an official candidate, O’Malley drew about 100 people to a union hall in Davenport, some pledging to support him and others there to compare him with the competition. A crowd more than double that size joined O’Malley later Saturday for the opening of his state headquarters on the outskirts of town here in the state capital, according to aides.

Many in the Davenport audience saw O’Malley in March when he headlined a well-attended dinner for the county Democratic Party.

“I brought something new with me today that I wasn’t able to say before … that I’m a candidate for the president of the United States,” an almost giddy O’Malley said, drawing hearty applause.

“That was the short version of the earlier talk,” he joked, referring to his announcement speech that morning at Federal Hill Park in Baltimore, the city where he lives and served as mayor for seven years.

O’Malley also received bursts of applause during his address as he pledged to strengthen bargaining rights for labor unions, break up big banks, expand Social Security benefits and fight a trade deal pending in Congress.

Local reporters seemed most interested, though, in how a candidate riding low in the polls would position himself not only against Hillary Rodham Clinton but also Sen. Bernie Sanders (I-Vt.), who has been drawing larger, enthusiastic crowds with his uncompromisingly liberal message.

O’Malley said he brings to the race not only “a fearlessness about my progressive goals” but something else: the accomplishments of running a state and a city for most of the past two decades.

“I believe I offer this alone among the candidates for the Democratic nomination: I have 15 years of executive experience, of actually getting things done,” he said. “Many of us talk about the things we should do, whether it’s increasing the minimum wage, whether it’s investing more in infrastructure and new industries to create more jobs. I’ve actually done those things.”

To become better known, he pledged to appear in as many of the state’s 99 counties “as I can possibly get to” and to engage all the time with both voters and the news media. Those comments were intended as a not-so-subtle contrast with Clinton, who has appeared in controlled campaign settings and fielded few questions from reporters since entering the race.

“This is the only way I know how to campaign,” O’Malley said. “This is how I was elected in 1999 in Baltimore City in a really, really tough point in our city’s history. This is how I was elected governor and defeated a Republican incumbent and how I was reelected over him by twice the margin. You have to engage, you have to talk.”

O’Malley was given a couple of other opportunities to directly criticize Clinton. He was asked, for example, what he thought of a string of news stories raising questions about donations from foreign governments, big banks and other moneyed interests to the Clinton Foundation.

“What I offer in this race is the independence to actually stand up to the bullies on Wall Street and make sure that they do not wreck our economy again like they did before,” O’Malley said.

O’Malley finds himself competing for the anti-Clinton vote against Sanders, a challenge that was illustrated Saturday by Bob Handel of Davenport, who sat in O’Malley’s audience wearing a “Bernie for President” T-shirt.

“We need a political revolution, like Bernie says,” said Handel, who described himself as a semi-retired real estate agent who has been drawn to Sanders’s commitment to helping the middle class and the poor.

Handel said he was impressed with O’Malley’s message, too, but is committed to Sanders, in part because of the devotion of a friend who was a big fan of Sanders and who died of a heart attack recently.

“I’m trying to pick up the slack for my friend,” he said.

Others in the crowd, including Democratic activist Sara Riley, said that although they like Sanders’s message, they don’t see a scenario in which a self-described socialist actually wins the nomination.

“I would say O’Malley is the alternative to Hillary,” said Riley, who had heard O’Malley talk on two previous occasions. “I love Sanders on the issues, but with the exception of some hard-core people who’ll support him no matter what, I think most people want someone who’d be a stronger general election candidate.”

Riley added that she will be “100 percent behind O’Malley” — unless her preferred candidate, Vice President Biden, gets into the race. “If he gets in, I’ll be like, ‘Bye Martin,’” she said.

O'Malley is scheduled to make several campaign stops Sunday in New Hampshire.