(CNN) The gloves are off and a new chapter in the long race for the Democratic presidential nomination is on.
With the first debate behind them, the crowded Democratic field starts a hectic, four-week sprint to their next opportunity to face off with each other at CNN's debate in Detroit. A new CNN poll released on Monday shows a significantly tighter race for the Democratic nomination after the debate, with Sens. Kamala Harris and Elizabeth Warren surging and former Vice President Joe Biden's lead over the field shrinking.
Biden receives support from 22% of registered voters who are Democrats or Democratic-leaning independents, with 17% backing Harris, 15% supporting Warren, and Sen. Bernie Sanders with the support of 14%. No one else in the 23-person field tested hits 5%.
Over the next two weeks, candidates will release their second quarter fundraising numbers, which will indicate which campaigns have the resources to mount significant fights for the Democratic nomination (and which do not). Already on Monday, South Bend, Indiana Mayor Pete Buttigieg's campaign announced he raised a massive $24.8 million, more than triple the amount it took during the first three months of the year.
Over a pair of two-hour debates in Miami this week, 20 of the 24 candidates vying for a chance to challenge President Donald Trump next year faced off for the first time in a contentious fight to set the terms of a contest that, even after months of campaigning, had yet to grab hold of the millions of voters who will decide its winner.
The crowded Democratic debate stages -- which hosted 10 candidates each night -- offered the candidates a chance to define themselves and label their rivals. In the process, they elevated issues of race, questions of public policy and, in a five-minute exchange that could echo deep into the primary season, saw the early frontrunner, Biden, knocked back on his heels by a searing attack from Harris of California.
Harris, a former prosecutor, used the skills she honed in the courtroom to question Biden's record on civil rights, in particular his opposition to federally mandated busing for school desegregation -- a charge the former vice president appeared unprepared for and, in moments, angered that he was being called on to defend. The back and forth ended with Biden, determined to escape Harris' crosshairs, cutting himself off and declaring, "My time is up."
As his aides and surrogates scrambled in the aftermath to recast the confrontation and Biden defended his record Friday in Chicago, his perceived status as the most "electable" Democrat in the field suddenly felt flimsy and the race more wide open than ever before.
The debates turned the page on the first chapter of the primary, which has already seen most of the two dozen candidates cycle through both early-voting states and less familiar stumping grounds as they try to carve out a connection with the diverse Democratic base. For the candidates seemingly moored to the lower tiers of early polling results, the large new audiences also presented an opportunity to introduce themselves -- and their ideas -- while launching tactical raids on some of the better-known contestants.
Their tussles further exposed divisions within the party, which have been litigated with increasing fervor since Trump's election in November 2016, as a new generation of more progressive lawmakers and activists seek to either push the establishment left -- or out of the picture entirely.
Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts, champions of that growing movement, were separated from a head-to-head clash by the chance of a random draw.
Debating on the first night, Warren aggressively made the case for the "big, structural change" she has promised throughout her nearly seven months on the stump. She also took the opportunity, during a standout moment, to close the gap with Sanders on his signature issue, "Medicare for All," by clearly stating her willingness to eliminate the private insurance industry.
Sanders drifted in and out of Thursday's debate, even as his ideas dominated large stretches of a contentious and sprawling conversation. His campaign made more noise in the aftermath, when health care -- and what it means to support Medicare for All -- became a post-debate point of contention. Harris, who raised her hand in the affirmative when the candidates were asked if they would abolish private insurance, said later she had misheard the question and still believed there was role to play for the industry.
"Let us all be very clear about this," Sanders said in a statement Friday, without naming names. "If you support Medicare for All, you have to be willing to end the greed of the health insurance and pharmaceutical industries."
Before that latest flare-up took over a slice of the post-debates news cycle, Obama administration Housing and Urban Development Secretary Julián Castro delivered an opening night performance that could lift his candidacy and, if he has his way, further undermine that of his fellow Texan, former Rep. Beto O'Rourke.
Castro pointedly challenged O'Rourke on immigration, escalating a simmering rivalry that came to a head when the former HUD leader -- in the course of a broad exchange over border policy and decriminalizing undocumented crossing -- questioned O'Rourke's competence and admonished him to "do your homework on this issue."
Immigration was top of mind for Democrats in Miami, in part because of the presence of a detention center for unaccompanied migrant children about an hour south in Homestead. Most of the candidates visited the makeshift protest encampment outside its fenced perimeter, with a number of them climbing stepladders to look in and wave into the distance at the child detainees.
"These were children who were being marched like little soldiers, like little prisoners, from one place to another," Warren, who was the first to make the trip, told reporters on Wednesday morning. "This is not what we should be doing as a country." Sen. Amy Klobuchar of Minnesota appeared at the same site hours later and over the next 48 hours the candidates seemed to arrive at the site in a constant rotation.
Back in Miami, Sen. Cory Booker of New Jersey used the first debate night to reintroduce himself to voters, talking at length about his roots -- and home -- in a majority-minority city, connecting the experience to his positions on gun control and civil rights. His performance paid off, literally, with an influx of 4,000 new online donors, making up 80% of his Thursday total.
Booker and Harris had been critical of Biden in the run-up to the debates, after the former vice president and longtime senator from Delaware recalled his time working alongside segregationist colleagues in the 1970s with, as they described it, tone-deaf and overly romantic language. Booker had been more forward in pursuing an explanation and apology from Biden last week, but it was Harris -- by chance because of the pre-debate draw -- who was served up the opportunity to zero in on his past positions and more recent remarks.
"Vice President Biden, I do not believe you are a racist," Harris said on Thursday night, immediately silencing the debate stage as the weight of the moment became clear, "and I agree with you, when you commit yourself to the importance of finding common ground. But I also believe -- and it's personal -- it was actually hurtful to hear you talk about the reputations of two United States senators who built their reputations and career on the segregation of race in this country."
Biden responded forcefully and unapologetically to Harris' challenge. He accused her of "mischaracterizing" his record on busing and in a quick but sharp jab that channeled progressive criticism of the former San Francisco district attorney, pointed out that he had chosen to become a public defender earlier in his career -- not, like Harris, a prosecutor.
Still, Harris emerged from her debate as a consensus winner, having put on display during a pivotal moment in her campaign all the traits that pundits and colleagues had figured would make her an estimable candidate. Voters noticed too and backed her during the debate with their pocketbooks, according to the campaign, giving individual online donations at 67% above the normal rate.
Race also featured prominently in South Bend, Indiana, Mayor Pete Buttigieg's debate strategy, though his goal was different: Defuse escalating tensions over his handling of the city's police department. Those questions existed from early on in his campaign, but became inescapable after a member of the force, responding to reports of car robberies, shot an African American man allegedly in possession of a knife. The killing set off protests in South Bend, with African American residents and others criticizing Buttigieg's oversight of the city's law enforcement apparatus.
Debate co-moderator Chuck Todd put the question bluntly to Buttigieg on Thursday night, asking why the South Bend police had not, over his time in office, grown more diverse along with the city.
"Because I couldn't get it done," Buttigieg said, offering a contrite tone at a moment when the anger and pain in South Bend remain raw. But his admission did little to cut off criticism from Rep. Eric Swalwell of California, who argued that Buttigieg should have fired the police chief because the officer did not have his body camera turned on at the time of the incident, a breach of policy.
Swalwell spent much of his time onstage Thursday picking out opponents for what he hoped would be memorable lines of attack.
Mostly, though, they fell flat. He repeatedly said it was time to "pass the torch," a generational argument first directed at Biden, who had made a similar appeal decades ago. On Thursday night, he brushed back the younger lawmaker with a firm rejoinder.
"I'm still holding on to that torch," Biden said.
This story has been updated with fresh developments from Monday.