LOS ANGELES (Reuters) - Billionaires and crystal-studded wine caves became the center of a spat as seven Democratic U.S. presidential contenders squared off in Los Angeles on Thursday for the final televised debate of the year.

After a policy-heavy first hour, in which the candidates offered their different takes on issues including taxes and trade, the sparring became more pointed and personal.

Here are some of the top moments from the candidates seeking their party’s nomination to challenge Republican President Donald Trump in November 2020.

‘DID IT CORRUPT YOU?’

In the night’s most explosive exchange, South Bend, Indiana Mayor Pete Buttigieg and U.S. Senator Elizabeth Warren argued over fundraising, with the senator from Massachusetts accusing the mayor of being influenced by wealthy donors.

“The mayor just recently had a fundraiser that was held in a wine cave full of crystals and served a $900-a-bottle wine,” Warren said. “Billionaires in wine caves should not pick the president of the United States.”

Buttigieg has repeatedly raised more money than Warren, who swore off all fundraising events and has been critical of any of her opponents who continue to hold fundraisers.

Buttigieg argued Democrats need to embrace, not snub, wealthy donors to help defeat Trump.

Then things turned personal.

“This is about issuing purity tests that you yourself cannot pass,” Buttigieg said, pointing out he has the smallest net worth of all the candidates. “Senator, your net worth is 100 times mine.”

Warren shot back.

“I do not sell access to my time,” she said. “I don’t do call time with millionaires and billionaires. I don’t meet behind closed doors with big-dollar donors.”

Buttigieg pointed out that as recently as last year, however, Warren did hold fundraisers.

Slideshow ( 11 images )

“Did it corrupt you? Of course not,” he said. “These purity tests shrink the stakes of the most important election.”

The two seemed ready to keep going until U.S. Senator Amy Klobuchar interjected.

“I did not come here to listen to this argument,” she said.

TRADE DEAL DRAWS SUPPORT AND OPPOSITION

Divisions also emerged over a new North American trade deal approved by the U.S. House of Representatives on Thursday. Progressive Senator Bernie Sanders said he opposed the pact, while moderate Klobuchar said she would vote for it.

The House approved the United States-Mexico-Canada Agreement (USMCA) with bipartisan support. Trump declared victory after its House passage, while Democratic leaders said it was an improvement over the current North American Free Trade Agreement (NAFTA) because it granted improved rights for workers.

Sanders reminded the audience that he also voted against NAFTA, unlike some other candidates on stage. The senator from Vermont said while the new trade deal was a modest improvement over NAFTA, it would not stop U.S. companies outsourcing American jobs overseas.

“It is not going to stop corporations going to Mexico,” Sanders said. “What we need is a trade policy that stands up for workers, stands up for farmers.”

Sanders added that the new deal never mentioned climate change, which he called an “outrage.” When the deal reaches the Senate, Sanders said he will not vote for it.

Klobuchar, from Minnesota, said she would be voting for it. “I believe we have change with this agreement,” she said, adding that it contained improved labor and environmental standards.

After the debate, a spokeswoman for Biden said he also supports the USMCA deal.

Slideshow ( 11 images )

CHINA

Buttigieg and former Vice President Joe Biden took on China, criticizing the authoritarian country’s actions against Democracy protesters in Hong Kong and Muslim Uighurs.

Buttigieg decried the “use of technology for the perfection of dictatorship” and warned that if elected president, he would lead a worldwide boycott of China if the regime resorted to the bloody tactics against pro-democracy protesters in Hong Kong that is used more than 30 years ago against protesters in Beijing.

“The message I will send is if they perpetrate a repeat of anything like Tiananmen Square when it comes to Hong Kong, they will be isolated from the free world and we will lead that isolation both diplomatically and economically,” said Buttigieg, who said he would consider boycotting the 2020 Olympics set for Beijing.

Biden said he would call for sanctions against China for its internment of Muslim Uighurs and would send “60% of our sea power to that part of the world” as a show of force, while building alliances with other Asian countries to further pressure China.

“We have to make it clear, ‘This is as far as you go, China,’” he said.

But Steyer rejected the idea of isolating China, saying the United States would have to continue to work with the economic and political powerhouse. “We can’t isolate ourselves from China,” he said. “We have to work with them as a frenemy.”

‘GET THINGS DONE’

Biden fused his regular plea that Democrats seek to unify the country after Trump leaves office with a response defending his son against continued attacks by Republicans.

“I refuse to accept the notion as some on this stage do that we can never, never get to a place where we have cooperation again,” Biden said. “If that’s the case, we are dead as a country.”

Attacks against Biden and his son Hunter are at the core of the accusation against Trump that led to the House impeaching him on Wednesday. Trump asked Ukraine’s president to investigate the Bidens, which the House argues was an abuse of power.

“If anyone has reason to be angry with the Republicans and not want to cooperate, it’s me. They have attacked me and my son and my family. I have no love,” Biden said. “But the fact is, we have to be able to get things done.”

GIFT OR FORGIVENESS?

In a nod to the holiday season, the candidates were asked if there was a fellow candidate on stage from whom they would ask for forgiveness, or a candidate to whom they would like to give a gift.

Entrepreneur Andrew Yang, the first to answer, was speechless for 10 seconds before laughing nervously. Eventually, he said Warren had done him the honor of starting to read his book and said, “I would love to give each of you a copy of my book.” Sanders later joked he could give all four of his books.

Warren looked slightly emotional when giving her answer. “I will ask for forgiveness,” she said. “I know sometimes I get really worked up, sometimes I get a little hot. What happens is if you do 100,000 selfies with people, you hear a lot of stories about people who are really down to their last moments.”

Klobuchar also asked for forgiveness “any time any of you get mad at me.”

“I can be blunt, but I am doing this because I think it’s so important to pick the right candidate here,” she said.