Key moments from Tuesday's Democratic presidential debate

The Democratic Party's direction and the viability of 10 of its presidential candidates were on the line in Tuesday's debate in Detroit and will be again Wednesday when 10 more hopefuls take the stage. A higher polling and fundraising threshold for participation in September's debates means that some won't make the cut. U.S. Sen. Amy Klobuchar of Minnesota was in pursuit of momentum. A marquee showdown pitted top progressives Sens. Bernie Sanders and Elizabeth Warren against each other. Mayor Pete Buttigieg and former Rep. Beto O'Rourke hoped to remain relevant. Here's a look at Tuesday's significant moments.

She didn't take the bait when she was asked to identify rivals who are making promises just to get elected. She did say that she doesn't back progressive plans to kick half of Americans off their health coverage or to give free college to wealthy kids. "I don't think we're going to do that," she said. "What I don't like about this argument is we are more worried about winning an argument than winning an election."

Bullock, a newcomer to the campaign and to the debate stage, used his opening remarks to introduce himself as a "pro-choice, pro-union populist Democrat that won three elections in a red state." Separating his views from progressives Sanders and Warren, he twice chided his rivals for "wish-list economics." Of Trump, he said, "Let's not kid ourselves: He will be hard to beat."

Buttigieg said that gun violence "is the worst part of being mayor" and added, "What we're doing hasn't worked." He called for red-flag laws to disarm abusers and the mentally ill and a ban on assault weapons like the ones he carried in the military. Noting that he was a student when the Columbine shooting occurred, he said, "something is broken. … We know what to do and it has not happened."

The ex-congressman tried an aggressive approach, going after Sanders and Warren in his opening statement and offering himself as an alternative to their progressive ideas. He argued that "Medicare for All, free everything and impossible promises … will get [President] Trump re-elected." Instead, he said, Democrats "can nominate someone with new ideas."

Replying to a question about whether Sanders is too extreme to beat Trump, Hickenlooper called ideas like Medicare for All and the Green New Deal "a disaster at the ballot box. You might as well FedEx the election to Donald Trump." Farmers need 10 years to recover from tariffs and factory jobs haven't been restored, he said. "We've got to focus on that and the economy and jobs and training."

O'Rourke said he would heal the racial divide by calling out Trump's "racism for what it is and also talk about its consequences." Without naming Minnesota U.S. Rep. Ilhan Omar, he alluded to Trump supporters' "send her back" chant and said, "hate crimes are on the rise every single one of the last three years." Americans must not just tolerate and respect their differences but "embrace them."

To revive factory jobs and align them with environmental incentives, the Ohio congressman promised to name a White House "chief manufacturing officer" to lead efforts to dominate markets for electric vehicles and batteries, charging stations and solar panels. "You cannot get there on climate unless we talk about agriculture," he said, pledging a "sustainable and regenerative"system to move away from subsidies.

"You're wrong," he said when he was asked to rebut Delaney's opening remarks in which the former congressman criticized Medicare for All. Noting that 500,000 Americans go bankrupt every year because of medical bills, he pointed to Canada's system as an alternative. "They guarantee health care … as a human right," Sanders said. "Health care is a human right, not a privilege. I believe that. I will fight for that."

Her remark that the nation is "not going to solve the urgent problems that we face with small ideas and spinelessness" helped spark intense sparring over the wisdom and workability of Medicare for All, which she supports. Asked if that system would result in higher taxes for the middle class, Warren said, "Costs will go up for billionaires and go up for corporations. For middle-class families, total costs will go down."

Williamson's plan to pay $200 billion to $500 billion in reparations to descendants of slaves is "payment of a debt that is owed," she said. "When it comes to the economic gap between blacks and whites in America, it does come from a great injustice that has never been dealt with," she said, and "anything less than $100 billion is an insult." There were about 5 million slaves at the end of the Civil War, she said.