By Cordelia Lynch and Emily Purser in Detroit
It was a battle for the ideology of the Democratic Party and a scrappy, rapid-fire experience.
Ten of the 20 leading Democrat candidates for the American presidency tried to convince voters why they stood apart from the rest on Tuesday night.
On the first of two nights of debate, they exchanged fiery critiques of each others' plans during a two-and-a-half hour event in Detroit. The second half of the field will debate tonight.
On a crowded stage, the two biggest names and the two progressives in the field arguably won out. But Senator Bernie Sanders and Senator Elizabeth Warren had a fight on their hands with the moderates that surrounded them.
Ms Warren and Mr Sanders defended their policies to give free healthcare to all Americans under sustained attack from more moderate candidates like former Maryland congressman John Delaney and Governor Steve Bullock of Montana.
"I don't understand why anybody goes through all the trouble running for president of the United States just to talk about what we really can't do and shouldn't fight for!" Elizabeth Warren responded to Delaney after one of his attacks.
She told Sky News: "Washington has worked great for decades for the wealthy and the well-connected.
More from US
"It just hasn't worked for the people right here in Michigan and this is a chance in 2020 to change that."
Among the candidates on the stage, three – Ms Warren, Mr Sanders and mayor of South Bend, Indiana, Pete Buttigieg – are polling in the top five candidates.
Several of the lower-polling candidates went on the offensive from the very start of the debate, seeking to create memorable moments to elevate their name recognition with voters.
John Delaney began with a full-throated attack on progressive policies, saying "free everything and impossible promises" would drive voters towards Donald Trump in November 2020.
Referring to Bernie Sanders' Medicare for All plan, he told Sky News: "Someone had to stand up and say this is a bad plan as a matter of policy."
Bernie Sanders, who became famous with many voters for his liberal ideas during the 2016 campaign, said he was "a bit tired of Democrats [who are] afraid of big ideas".
Debate watchers were also looking for a strong performance from 37-year-old Pete Buttigieg, who gathered a lot of momentum in the early stages of the campaign by positioning himself as the millennial alternative to septuagenarian Donald Trump.
He sought to cement that strategy during the debate by repeatedly referencing his age. On mass shootings, Buttigieg said: "This is the exact same conversation we've been having since – since I was in high school.