Ten Democratic presidential hopefuls have clashed in a televised US debate that laid bare the party's deep divisions over how best to win in 2020.
Elizabeth Warren and Bernie Sanders, the most liberal candidates in the crowded field, came under attack from their more moderate colleagues.
The three women and seven men on stage in Michigan debated healthcare, border policy and how to defeat Donald Trump.
Ten more Democrats, including Joe Biden and Kamala Harris, will debate on Wednesday.
The winner of the Democratic presidential nomination will be announced next July at the party convention. The presidential election will take place months later, in November.
Several candidates began the debate in Detroit by criticising as unrealistic the policies of Ms Warren and Mr Sanders and not the best way for the party to defeat President Trump.
Who was on stage?
The line-up was chosen at random by CNN:
- Massachusetts Senator Elizabeth Warren
- Vermont Senator Bernie Sanders
- South Bend, Indiana, Mayor Pete Buttigieg
- Former Texas Congressman Beto O'Rourke
- Minnesota Senator Amy Klobuchar
- Ohio Congressman Tim Ryan
- Former Maryland Congressman John Delaney
- Montana Governor Steve Bullock
- Former Colorado Governor John Hickenlooper
- Author Marianne Williamson
What was the key flashpoint?
Healthcare, which has been an important issue for Democrats and was a focus during last year's mid-term elections, was a point of contention on Tuesday night.
The first question posed to the candidates was whether Mr Sanders' plan for a single-payer health system, Medicare for All, would be "political suicide", but healthcare was a recurring topic throughout the debate.
The candidates sparred over enacting Medicare for All versus expanding on former President Barack Obama's signature policy, the Affordable Care Act, which extended health insurance coverage in 2010.
Mr Ryan and Mr Delaney, who has worked in the healthcare industry, were among those who attacked Mr Sanders' plan, saying it would negatively impact on working-class Americans by taking away their employer-sponsored health benefits.
Mr Sanders focused on how millions of Americans remain underinsured or uninsured while the health industry makes billions in profits.
Ms Warren sought to refocus the matter slightly, saying that no Democrat is "trying to take away healthcare from anyone", and that Democrats "should stop using Republican talking points" to discuss with each other.