MIAMI — At the first debate of the Democratic presidential primary, Sen. Elizabeth Warren and the other nine candidates on stage Wednesday charged that the "rigged" economy under President Donald Trump is benefiting only the rich, while they disagreed over the border crisis, military power and how to improve the nation's health care system.

Pressed about her plans to enact sweeping economic changes, such as a new tax on wealth, Warren said that although the economy is growing, it's only helping the wealthy and corporations — "drug companies, but not people who need to get their prescription filled," she said.

Other candidates agreed the economy is not working for many Americans.

Sen. Amy Klobuchar, D-Minn., said Trump "gloats" in the White House while average people are hurting, and former Texas Rep. Beto O'Rourke switched to Spanish to speak about inequities, then returned to English to slam the "rigged" economy.

Candidates had one minute to respond to questions and 30 seconds for follow-ups, but they often jumped in to interject themselves after others spoke and frequently called out to the moderators when they felt they weren't getting enough time.

The candidates rarely mentioned Trump by name. And while there were occasional sharp contrasts on policy, the tenor was nothing like the acerbic faceoffs of the 2016 Republican primary, although those on the stage didn't hesitate to point out their policy differences.

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Mostly, the contenders focused on introducing themselves and their ideas to voters.

On health care, only two hands went up — that of Warren and New York City Mayor Bill de Blasio — when the candidates were asked who would be willing to abolish private health insurance to implement a single-payer health care system.

Warren has previously left some ambiguity about whether she'd support eliminating private insurance. But she made it clear during the debate that "I'm with Bernie on 'Medicare for All,'" perhaps hoping to attract voters from Sen. Bernie Sanders, I-Vt., who will debate Thursday.

Most of the other candidates in the race support alternative plans that would allow Americans to buy into a public option, like Medicare, while also preserving private insurance for people who want to keep it.

When O'Rourke explained why he would let Americans keep their private plants, de Blasio saw an opportunity to strike. "Why are you defending the private insurance industry?" he said from across the sage.

Former Maryland Rep. John Delaney, a political moderate and former health executive, jumped in by saying single-payer health care would wipe out good union insurance plans, like the one his father had, and said it would essentially collapse the American health care system.

"To some extent, you're supporting a bill that would have every hospital close," he said to those on the stage supporting single-payer health care.

On a related issue, Klobuchar laughed when Washington Gov. Jay Inslee said he was the only candidate on stage who had signed a bill to support abortion rights and reproductive health care.

"There are three women up here who have fought pretty hard for a woman’s right to choose," she said to cheers.

Immigration saw some fierce disagreement among the candidates, several of whom switched between English and Spanish as they debated one of Trump's signature issues.

Former Housing Secretary Julián Castro called for repealing the law that criminalizes illegal border crossings and took aim at O'Rourke for what he suggested was empty rhetoric.

"If you did your homework on this issue, you would know," Castro said to his fellow Texan.

It was one of at least three times that candidates ganged up on O'Rourke, who entered the race with high prospects but has seen his poll numbers fall.

O'Rourke defended himself by saying Castro was just "looking at a small part" of the immigration problem, while he wanted to overhaul the entire system. Castro fired back by saying, "That’s not true" before diving into details of immigration law.

Earlier in the day, several candidates visited a private facility in Homestead, Florida, where child migrants are being temporarily held for processing. Sen. Cory Booker, D-N.J., said at the debate that it's "repugnant" that people are profiting from the migrant crisis.

The candidates were largely unified, however, on the scourge of gun violence in America, all calling for stricter rules on firearms and expanded background checks.

Booker, the former mayor of Newark who still lives in the troubled city, said that while others hear about gun violence, he literally hears gunshots in his neighborhood, explaining that someone he knew personally was shot and killed with an assault rifle on his block last year.

"If you need a license to drive a car, you should have a license to own a firearm," Booker said, noting not everyone on the stage supports a gun licensing scheme.

All the candidates agreed on the need to fight climate change, but Inslee tried to differentiate himself by saying he’s the only candidate who would focus on it above all else.

"This has to be the top propriety of the United States, the organizing principle to mobilize the United States so we can do what we have always done, lead the world and invent the future," Inslee said.

Rep. Tim Ryan, who represents a struggling post-industrial part of Ohio, said the only way to address climate change and beat Republicans is to convince workers that a green economy will help them by showing them Democrats are not "elite, coastal and Ivy league."

"If we want to beat Mitch McConnell, this better be a working-class party," he said.

Ryan also sparred with Rep. Tulsi Gabbard, D-Hawaii, on foreign policy.

Gabbard, an Iraq War veteran and frequent critic of U.S. foreign policy, shot back at Ryan after he said the United States needs to stay "engaged" in hotspots like Afghanistan.

"As a soldier, I will tell you that answer is unacceptable," Gabbard said, urging the U.S. to pull back and focus on America.

"When we weren’t there, they started flying planes into our buildings," Ryan replied. "If we go in there and say we want to withdraw from the world — that’s what President Trump is saying."

Gabbard noted it was Al Qaeda, not the Taliban, that attacked the U.S. on Sept. 11, 2001, and said, "The Taliban was there long before we got in and will be there long after we leave."

The debate is the first chance many Americans are getting to see the largest and most diverse presidential primary field in history.

The debate was moderated by Savannah Guthrie of "Today," Lester Holt of "Nightly News," Jose Diaz-Balart of Telemundo, Rachel Maddow of MSNBC and Chuck Todd of "Meet the Press."

Twenty of the 25 declared candidates qualified for the Miami debate, which will continue Thursday night with another slate of 10 contenders, including former Vice President Joe Biden, Sanders and Mayor Pete Buttigieg of South Bend, Indiana.