With such a crowded stage, it was a struggle for any one candidate to rise above the others. But here are the standout moments.
WESTERVILLE, Ohio -- Who won, if anyone?
"You have to beat the champion to take the crown, and in that sense Elizabeth Warren came into this debate on top and and she left it on top," said David Niven, a political science professor at the University of Cincinnati, following Tuesday night's three-hour Democratic match-up in Westerville.
"She had the most opportunity, and she used it well to articulate her values and solidify her place in the center of the race."
But before the Massachusetts senator's supporters start polishing her crown, have a look at what Aaron Kall, director of debate at the University of Michigan, says.
"I definitely think Warren lost," he said after watching the contest from the press center next to the debate site, Otterbein University's Rike Center.
"The biggest question is who the biggest beneficiary is going to be."
Larry Sabato, director of the University of Virginia’s Center for Politics, didn't pick a winner. But he said via Twitter, "This is the Elizabeth Warren debate. You might be happy or sad about it, but she's the one who is setting the tone and she's the reference point for most of the other candidates. That happens to the frontrunner."
With almost 23 minutes of speaking time, Warren easily got the most exposure during the Ohio debate, a New York Times compilation shows.
Next was former Vice President Joe Biden, at just under 17 minutes, followed by Minnesota Sen. Amy Klobuchar, former Texas Congressman Beto O'Rourke, Vermont Sen. Bernie Sanders and South Bend Mayor Pete Buttigieg, all clustered at a little over 13 minutes. California billionaire Tom Steyer got the least mic time, clocking in at 7 minutes and 13 seconds.
“Like trying to win an Oscar in a movie with a huge ensemble cast, it is really hard for any of these candidates to hold the spotlight in this debate,” Niven said.
"The candidates remembered their lines. Nobody Rick Perryed themselves out of the race tonight,” he added, citing the former Republican Texas governor infamously remembered for not remembering which cabinet agencies he wanted to abolish.
Sabato agreed: "Too many candidates and too many topics mean zigzagging from issue to issue and person to person. It's a big blur."
Kall said, "Really, none of the other candidates had enough time to make a positive performance."
Buttigieg criticized Warren for ignoring a CNN questioner's "yes or no" query about whether her Medicare for All plan would increases taxes for the middle class, calling it "a yes or no question that didn't get a yes or no answer."
He also launched a digital ad bashing Warren and Sanders for their healthcare plans.
Klobuchar also hit Warren for the dodge: “At least Bernie's being honest here and saying how he's going to pay for this and that taxes are going to go up. And I'm sorry, Elizabeth, but you have not said that, and I think we owe it to the American people to tell them where we're going to send the invoice. ... You are making Republican talking points right now in this room."
Biden also chided Warren for fuzziness on who picks up the bill for her proposal.
"Sen. Warren is now the center of the universe. The jabs that used to be aimed at Biden are all targeting Warren now," Niven said.
Kall compared Warren's role as dartboard Tuesday night to the experience of Biden after earlier Democratic debates.
"All the other candidates sort of know the nomination runs through her ... she was on the defensive for so long," Kall said. "At the same time, it wasn’t a total implosion. But after that shakiness, I think voters will ask could she stand on a stage with (President Donald) Trump for 90 minutes."
Both Kall and Niven said Sanders' performance seemed to alleviate fears about his health after a heart attack this month.
Biden was aided by the minimal time spent on the unsupported accusations from Trump about the former vice president's role with his son in Ukraine and China. However, his story didn't quite match his son's from an interview earlier Tuesday: the elder Biden said he never discussed his son’s Ukraine dealings with him, while Hunter Biden acknowledged that he had spoken briefly with his father about work for the Ukrainian company, Burisma Holdings.
Biden “again muddled through most of the night ('Secondly, I mean thirdly') before snapping to life in the closing moments,” Niven said by email. Biden also momentarily mixed up Iraq and Afghanistan.
Kall said, "If Biden doesn't gain from (Tuesday's) debate, Pete Buttigieg is the next most likely candidate to prosper despite a lack of equitable speaking time. He had favorable exchanges with (Hawaii Congresswoman) Tulsi Gabbard and Beto O'Rourke, while deftly brandishing his military and national security credentials. Other candidates like Amy Klobuchar, (former HUD Secretary) Julian Castro and (New Jersey Sen.) Corey Booker also had solid debate performances, but all three are so far back in the polls that it's probably impossible for them to bridge such a large gap by the time voting begins in early 2020."
Gabbard said the ongoing slaughter of Kurdish forces that American troops were protecting is a result of "the regime-change war that we’ve been raging in Syria" and that "Trump has the blood of the Kurds on his hands."
Buttigieg, a military veteran like Gabbard, pushed back that she was "dead wrong," saying the assault by Turkey is solely Trump's fault: "a consequence of a withdrawal and a betrayal by this president of American allies and American values."
Castro stumbled factually when he said Ohio has lost jobs under Trump. In just the past 12 months, Ohio has gained 31,000 jobs and has a net increase since Trump took office in January 2017.
Kall's takeaway when the debate was finally over: "In reality after (Tuesday) there are four candidates. Some of the rest are simply auditioning for vice president."
The quartet: Warren, Biden, Sanders and Buttigieg.