Hillary Clinton and Bernie Sanders have clashed over US involvement in the Middle East and gun control in the first Democratic presidential debate.
The pair outlined competing visions for a party seeking to keep the White House for a third straight term, but in a moment of political unity - and levity - Mr Sanders leapt to Mrs Clinton's defence on the issue of her controversial email practices.
"The American people are sick and tired are hearing about your damn emails," Mr Sanders said as the crowd in Las Vegas roared with applause.
A smiling Mrs Clinton reached over to shake his hand and said: "Thank you, Bernie."
While the five candidates onstage took issue with each other, they also repeatedly sounded traditional Democratic themes - such as fighting income inequality - that are sure to carry over to the general election campaign against the Republicans.
Throughout most of the two-hour debate Mrs Clinton played the role of aggressor, an unexpected shift for the Democratic front-runner who had barely mentioned her rivals since launching her campaign six months ago.
Until now, Mrs Clinton and Mr Sanders - who has emerged as her toughest competition - have circled each other cautiously and avoided personal attacks.
After the Vermont senator, a self-described democratic socialist, derided "a casino capitalist process by which so few have so much", Mrs Clinton said it would be a "big mistake" for the US to turn its back on the system that built the American middle class.
Asked whether she thought Mr Sanders, who has a mixed record on gun control legislation, had been tough enough on the issue, she said: "No, I do not."
Mr Sanders defended his record and called for better mental health services, stricter background checks and closing a loophole that exempts gun shows from background checks.
The two also tangled over foreign policy, an issue where Mrs Clinton is often more hawkish than others in the Democratic Party.
The former secretary of state reiterated her call for more robust US action to stop the Syrian civil war and defended her judgment on international issues, despite having voted for the 2002 invasion of Iraq.
Mr Sanders called the Iraq war "the worst foreign policy blunder in the history of our country" and said he would not support sending American combat troops back to the Middle East to fight terrorism.
"Nobody does, Senator Sanders," Mrs Clinton interjected.
Joining them on stage was a trio of low-polling candidates looking for a breakthrough moment: former Maryland governor Martin O'Malley, Jim Webb, a former navy secretary and US senator from Virginia, and former senator and governor Lincoln Chafee, the Republican-turned-independent-turned-Democrat from Rhode Island.
Also hanging over the debate were the lengthy deliberations of Joe Biden, who is weighing a late entry into the Democratic race.
Debate host CNN kept an extra podium on standby in case Mr Biden decided to show up, but the vice president stayed in Washington, watching the debate at his residence.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article