Bernie Sanders and Hillary Clinton came out swinging in a fiery, high-stakes debate on CNN Thursday night, as he cast doubt on her judgment and she criticized his command of policy and record on guns.

Sanders accused his Democratic presidential rival of “lacking the kind of judgment we need to be the kind of president we need.” But he found himself on defense for not releasing his taxes and said he would do so on Friday.

Clinton again found herself on defense for her paid speeches to big banks, declining to release the transcripts when pressed by CNN moderators. But she counter-punched by referring to the Vermont senator’s trouble explaining some of his core policies in an interview with the New York Daily News.

The debate and the New York primary on Tuesday come at a critical juncture in the Democratic contest, as Sanders tries to change the dynamics of a race that has delivered many more delegates to Clinton, while the former secretary of state tries to halt an unexpectedly strong challenger who can claim he has momentum on his side.

The debate was the most combative yet, with the two delivering harsh attacks that at points needed intervention from the moderators. The rowdy crowd, meanwhile, stoked the tension, loudly cheering and hissing throughout the exchanges.

Attacks on Wall Street

The event, held just across the river from Wall Street, in the Brooklyn Navy Yard, quickly turned to the issue of the big banks and their perceived excesses.

When asked to name a single policy decision Clinton made as senator that showed she was favoring the banks, Sanders said that when the “greed and recklessness and illegal behavior of Wall Street” led to the financial crisis, he had called on the big banks to be broken up — while Clinton was “busy giving speeches to Goldman Sachs.”

Clinton shot back: “He cannot come up with any example because there is no example … It’s always important — it may be inconvenient — but it’s always important to get the facts straight.”

When she also said that she had spoken out against the big banks for the actions, Sanders took a mocking tone.

“Oh my goodness, they must have been really crushed by this,” he said, asking whether her statements came before or after “receiving huge sums” from the banks in speaking fees.

Clinton was pressed by CNN co-moderator Dana Bash on why she would not release the transcripts from the speeches she made to Goldman Sachs and put the issue to rest. Clinton answered: “There isn’t an issue. When I was in public service serving as the senator from New York, I did stand up to the banks.”

Clinton — as she has in the past — asked that there be the “same standard for everybody,” saying she would be happy to release the transcripts if other presidential candidates, including Donald Trump, did the same.

She then turned the tables on Sanders and his tax returns, saying: “Set the same standard on tax returns. Everybody does it — and then we move forward.”

Sanders, who has come under pressure to release his tax returns, vowed on the CNN debate stage to release his previous year’s return on Friday. Returns from earlier years, he said, would also be released “very shortly.”

Firing on gun control

The two also displayed intense friction over gun control.

Throughout the election, Clinton has criticized Sanders’ record in Congress on gun control — an attack she once again made forcefully on Thursday night. Clinton accused Sanders of having made a “commitment to the NRA” to oppose a waiting period for background checks on gun purchases — and slammed the senator for voting against the so-called “Brady bill” five times.

Sanders was also forced to address one particularly difficult issue related to guns.

Recently, the daughter of the Sandy Hook Elementary School principal who was killed at the Newtown massacre asked that the senator apologize to the victims for “putting the gun lobby above our families.”

Asked Thursday whether he would apologize, Sanders punted. Pressed a second time by Blitzer, Sanders said he did not believe he owed them an apology but that he would support their right to sue gun makers.

While speaking of the crime bill Clinton’s husband Bill ushered in as president, Sanders called a term she had used in the 1990s — superpredator — “a racist term.” She has since said it was a word she shouldn’t have used.

Differences on Israel

The second hour of the debate exposed a major foreign policy disagreement between Clinton and Sanders on the Israeli-Palestinian conflict.

Sanders recently said that Israel’s response in the 2014 Gaza war was “disproportionate.” On the debate stage, the senator labeled himself “100% pro-Israel” and said that the point of those controversial comments had been to emphasize that that Palestinian people must be treated with respect and dignity.

“That does not make me anti-Israel,” Sanders said.

Clinton, who used the discussion to highlight the extensive role she played as Secretary of State in negotiating a ceasefire between Israel and Hamas in 2012, said Israel is under “constant threat.”

“I don’t know how you run a country when you are under constant threat. Terrorist attacks, rockets coming at you — you have a right to defend yourself,” she said.

Sanders responded by accusing Clinton of failing to answer the question of whether Israel’s response was disproportionate. “You evaded the issue,” he said. In a major speech to AIPAC, Sanders said his rival had “barely mentioend the Palestinians.”

“We cannot continue to be one-sided,” he said.

Clinton, once again, suggested that Sanders likes to point out problems without having a fully though-out solution to address them.

“Describing a problem is a lot easier than trying to solve it,” she said.

Minimum wage debate

The heated debate also quickly exposed tensions between Clinton and Sanders on the issue of income inequality — specifically, raising the minimum wage.

Asked whether she would sign a bill raising the federal minimum wage to $15, Clinton responded: “Of course I would.”

That response drew this skeptical reaction from Sanders: “I am sure a lot of people are very surprised to learn that you support raising the minimum wage to $15 an hour. That’s just not accurate.”

In one of the most animated exchanges of the evening, the two candidates began to talk over one another, eventually prompting moderator Wolf Blitzer to intervene.

“If you’re both screaming at each other, the viewers won’t be able to hear either of you,” Blitzer said. The crowd, for its part, was much rowdier than at previous Democratic debates, cheering and hissing throughout the event.

Sanders insisted that while he has long been fighting to raise the national minimum wage to $15, Clinton had only advocated to raise it to $12. “Twelve dollars is not good enough, we need $15 an hour,” Sanders said.

On environmental issues, their differences highlighted a fundamental contrast between the pair’s approaches: Clinton’s calls for pragmatism and Sanders’ calls for a political revolution.

Clinton lauded the global climate change pact reached in Paris, calling it a “major accomplishment.”

“Our president led that effort to protect our world and he deserves our appreciation, not our criticism,” Clinton said.

But Sanders argued that while the agreement was a “step forward” in the right direction, it wasn’t enough.

“Incrementalism and those little steps are not enough,” he said, before accusing Clinton of having supported fracking technology — a drilling technique that has created a major boom in oil and natural gas but raised environmental concerns — around the world as secretary of state.

Clinton responded that she was “bewildered” by Sanders’ remarks.

“It’s easy to diagnose the problem. It’s harder to do something about the problem.”

Until recently, the Democratic race had remained relatively tame, largely devoid of the personal attacks and heated rhetoric that have characterized the GOP contest.

Race heats up

But as the race has dragged on into April, there has been a shift.

In recent days, Sanders has questioned Clinton’s judgment and credibility, pointing to her relationship with Wall Street and vote for the Iraq War.

Clinton, meanwhile, has had harsh words for Sanders, sharply questioning whether he is capable of executing the promises embedded in his lofty rhetoric.

And Clinton and her aides had been signaling for days that they planned to hit Sanders for his views on gun control, particularly his belief that victims of gun violence should not be able to sue gun and ammunition manufacturers.

The likelihood that this issue would become a flashpoint on Thursday skyrocketed earlier in the day when a judge in Connecticut ruled that the suit between the families of Sandy Hook victims and the manufacturer of the gun used in the 2012 shooting there could go forward.

The viability of the lawsuit was in doubt because of the Protection of Lawful Commerce in Arms Act, a law Sanders supported that protects gun manufacturers from liability.

Clinton hit Sanders for the law at a roundtable on gun violence on Monday and is likely to do so again Thursday night.

Sanders is also poised to have to address the latest controversy that has engulfed his campaign: On Wednesday, surrogate Paul Song said at a campaign rally that the Democratic party must stop electing “corporate Democratic whores.”

Sanders quickly disavowed those comments, calling them “inappropriate and insensitive.”

The locations of the debate, across the East River from Manhattan, make it a home-turf battle for both candidates.

Clinton served as a New York senator for eight years and Brooklyn is the location of her campaign headquarters, while Sanders was born and raised in the borough.

In her opening statement, Clinton began with an oblique attack on the GOP, defending the “New York values” that Republican presidential candidate Ted Cruz, a Texas senator, has used as a pejorative.

Speaking of her days representing the state in the U.S. Senate, she said, “We worked hard to really keep New York values at the center of what we are and what we do together.”

Polls show Clinton is likely to defeat Sanders in New York, and even as she enjoys a sizable delegate lead, it is critical for Clinton that she win this state.

The Democratic race so far has proven Sanders to be an unexpectedly durable candidate whose popularity among liberals and younger voters has helped to expose the vulnerabilities in Clinton’s candidacy.

The New York race comes after a string of victories for Sanders in states including Wyoming, Wisconsin, Idaho and Utah. If Sanders were to eke out a win in New York, it would deal a serious blow to Clinton and strengthen the narrative that it is taking Clinton much longer than initially expected to clinch her party’s nomination.