CEDAR RAPIDS, Ia. — In his first visit to Iowa since declaring he would run for president, Joe Biden lived up to the "Middle Class Joe" nickname he has long used for himself.

"I think the moral obligation of our time is to rebuild the middle class. That’s my north star," Biden said. "And the reason is, if the middle class does well, everybody does well."

The former vice president also promised Iowa Democrats that "you're going to see a whole heck of a lot of me" on the campaign trail.

"No one’s going to work harder in Iowa than Joe Biden," he said.

It was part of his pitch to Iowa voters that he is best positioned in field of more than 20 Democrats to win back the White House and restore the moral direction of the country.

With the kickoff of his third presidential campaign last week, Biden, 76, returned to Iowa as a frontrunner, joining a historically large, diverse field of candidates running to unseat President Donald Trump. Biden has framed his campaign as "a battle for the soul of our nation."

That appeals to Paulette Ash, an undecided caucusgoer from Cedar Rapids, who said she thinks Biden has something the other candidates don't.

"I think Trump's scared of Joe Biden, and I think that's the only one he's scared of," said Ash, who also likes California Sen. Kamala Harris.

Trump singled out Biden on Twitter, taunting him Monday by calling him "Sleepy Joe."

Biden has led the last two Des Moines Register/CNN/Mediacom Iowa Polls, which surveyed likely Democratic caucusgoers.

In the most recent poll, conducted in March, 27% of respondents said Biden is their first choice for president, and another 19% said he is their second choice. He is viewed favorably by 81% of likely Democratic caucusgoers — at least 10 points higher than for any of the 22 other people tested.

'I'm a union guy'

Biden's first Iowa stop, in the basement of the Veterans Memorial Building in Cedar Rapids, included a speech to a crowd of about 300 that was heavy on worker-friendly themes like raising the minimum wage to $15 an hour, making community college free and making it easier for workers to join a union. About a dozen people wore bright yellow "Firefighters for Biden" T-shirts.

"I want to make no mistake about it. I’m a union guy," Biden said.

He advocated for repealing the 2017 tax cuts signed last year, but said his priorities could be achieved without raising taxes beyond that.

"We can do all that we need to do to make this country grow and restore the dignity of work, all the things we have to do, if we just eliminate unnecessary loopholes. We don’t have to raise any new taxes," he said, drawing a distinction between himself and some of his competitors, including Massachusetts Sen. Elizabeth Warren, who has proposed a tax on the ultra-wealthy.

Biden echoed the message in an evening speech in front of a larger crowd in Dubuque. But the event began on a somber note as state Sen. Pam Jochum introduced Biden by reading a letter the former vice president wrote her after her daughter, Sarah, died last year at age 41 of a brain injury caused by a fall at home. Biden's son, Beau, died of brain cancer in 2015.

"For us, some days are harder than others but our beautiful memories of our kids will always be with us," Biden wrote to Jochum at the time.

"Joe Biden is fundamentally caring, generous and kind. His values, his morals are the polar opposite of Donald Trump’s," Jochum said.

Biden: On health care, give Americans a public option

Biden also detailed his position on health care, touting the Affordable Care Act, which he helped pass as President Barack Obama’s vice president and promising to "make sure we finish the job on health care," which he said, "should be a right."

The way to do that, he said, is to allow Americans a public option to buy into government health care programs like Medicare.

Biden is seen as more moderate than several other Democratic presidential contenders who support a "Medicare for All" universal health care program. In a sign that the party has moved further to the left than when the Affordable Care Act was passed in 2010, Biden’s speech came the same day as congressional Democrats held their first hearing on Medicare for All in Washington, D.C.

Jacy Ahmed, a 42-year-old who owns a cleaning company in Cedar Rapids, said she doesn't necessarily support Medicare for All, but she thinks the health insurance system needs to change somehow.

"I like the idea of there still being options but I want it to open up more so that more people are insured so that maybe the costs will go down so that it feels like we’re more taken care of," she said.

Ahmed said she's always considered herself "very far left leaning" but this is the first election where she feels like her views are more down the middle of the Democratic party's positions. She said she's still undecided but likes both Biden and South Bend, Indiana Mayor Pete Buttigieg.

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Some voters considered Biden's bipartisan credentials to be a strength.

Matt Wright, a Dubuque resident, said he is typically conservative but will caucus for a Democrat because he can't support Trump.

"He’s worked with Republicans and Democrats and really is a candidate that is more likely to appeal to people like me who traditionally might vote Republican but just definitely can’t with the current candidate," said Wright, who is still undecided.

Biden's decades in politics could work against him, particularly as voters force him to account for past actions that now are at odds with the party's base. Among them, he championed a 2005 bankruptcy law that weakened protections for some consumers.

Biden also likely will be asked to account for his support of the 1994 crime bill that helped lead to a wave of mass incarceration, particularly for minorities, as well as his treatment of Anita Hill during the confirmation hearings of Supreme Court Justice Clarence Thomas.

At both events, Biden did not take questions from the audience, but stayed to shake hands and take selfies.

After the event in Dubuque, 77-year-old Sandra Wilke emerged from the rope line clutching a "Biden for president" sign to her chest and exclaiming, "I got a hug!"

But Wilke, who said she hopes Biden is the Democratic nominee, said she also gave the former vice president a bit of advice.

“I told him: You have to say 'together, we can.’ Don’t say, ‘I' or 'I will,'" Wilke said. "Say, ‘Together, we can."

Sunglasses, ice cream

On Tuesday afternoon Biden also made an unannounced stop at The Cone Shoppe in Monticello, where, surrounded by more than a dozen members of the media, he ordered a chocolate and vanilla twist ice cream cone.

"It’s a heck of a thing after all these years to be known for two things: sunglasses and ice cream," he said.

He left $40 to pay for ice cream for the other diners.

Biden will continue his trip through Iowa Wednesday with planned stops in Iowa City and Des Moines on Wednesday.