Hillary Clinton and Beie Sanders sparred over gun control at Sunday’s debate in Flint, Mich., with Clinton using the Sandy Hook massacre to make a point about holding gun makers responsible for crimes – and Sanders arguing that position would effectively mean an America without guns.

The flashpoint was Sanders’ past support for a bill to help protect gun manufacturers and sellers from lawsuits.

Sanders defended his decision, saying that if gun sellers and makers are held liable in many of these cases, “What you’re really talking about is ending gun manufacturing in America.”

Clinton countered that no other industry in America has “absolute immunity,” and invoked the Sandy Hook mass shooting.

“You’re not the only person whose heart was broken,” Sanders said.

The two candidates also clashed at the CNN-hosted debate over the economy, with Clinton slamming her rival for opposing the auto bailout – and Sanders ripping the front-ruer for her past positions on trade.

The clashes came after Sanders won the Maine Democratic caucuses, the Associated Press reported, adding to wins the night before in Nebraska and Kansas — by far the most successful two days of his campaign.

Sanders rode to victory in Maine in part on a huge tuout — Sanders beat Clinton by a ratio of nearly 2-to-1. The tuout was so big Sunday that some voters had to wait in line for more than four hours in Portland.

The victory gives Sanders a total of three victories over the weekend to Clinton’s one.

As he tries to catch up to Clinton’s still-substantial delegate lead, Sanders went after her aggressively at Sunday’s debate for her support for what he called “disastrous trade agreements” like NAFTA.

She countered by pointing out he opposed the auto industry bailout.

He tried to describe it as the Wall Street bailout, and got a little feisty when she started to speak over him.

“Excuse me, I’m talking,” he said. “Your story is for voting for every disastrous trade agreement.”

Clinton then called him a “one-issue candidate.”

And on the auto bailout, she said, “If everybody had voted the way he did, I believe the auto industry would have collapsed, taking 4 million jobs with it.”

“My one issue is trying to rebuild a disappearing middle class. That’s my one issue,” he said.

Meanwhile, at the top of Sunday’s debate, Clinton and Sanders momentarily set aside their differences – to lament the plight of the people in the host city of Flint, Mich., and call for the goveor’s resignation over the toxic water crisis.

Sanders said he’s met with families impacted by the crisis, and “What I saw literally shattered me.”

Sanders said there’s “blame to go around” but Republican Gov. Rick Snyder should resign.

Clinton echoed the remarks, saying, “Amen to that.”

“The goveor should resign or be recalled,” she said, while also calling on the federal and state govements to send more money to the city to fix infrastructure.

The city’s water crisis started when the city switched to the Flint River in 2014 while under a state-appointed emergency manager. While the state has taken much of the blame, officials with the city and federal govement – as well as the state – have also resigned.

Clinton faced Sanders on the debate stage Sunday night as she fights to shake her primary rival – and coect with voters still hesitant about her campaign – while the hard-charging Vermont senator keeps notching just enough primary and caucus wins to keep his campaign alive, and a threat to her bid.

The two candidates entered the CNN-hosted debate in the beleaguered city of Flint, Mich., as the two continued to effectively split recent primary and caucus contests.

The results from Maine Sunday aren't binding, but will be used to select a slate of delegates to the state convention, where national delegates will be elected. Maine will send 25 delegates and 30 superdelegates to the national convention in Philadelphia.

On Saturday, Sanders won the Nebraska and Kansas caucuses, while Clinton claimed the bigger Louisiana primary.

And on Super Tuesday this past week, Clinton won seven states to Sanders’ four.

Because Clinton’s wins have not only been more numerous but more valuable, the former secretary of state is only adding to her delegate lead over Sanders – which before the Maine contest stood at 1,121 to 481.

Clinton’s delegate count includes superdelegates -- members of Congress, goveors and party officials who can support the candidate of their choice. It takes 2,383 delegates to win the nomination.

But Sanders, even by wiing lower-profile contests, has managed to at least demonstrate lingering weaknesses in the front-ruer’s campaign as he draws an enthusiastic response in the grassroots-driven caucus states.

Bigger tests loom, however, with Michigan and Mississippi voting this Tuesday – and Ohio, Florida and more going to the polls the following week.

Sanders wrote in Sunday's Detroit Free Press that nowhere are his differences with Clinton, a former secretary of state and senator, stronger than on trade. He also renewed his criticism of Clinton’s support for the North American Free Trade Agreement and normalized trade relations with China.

With Clinton continuing to widen her considerable lead in the Democratic delegate count, Sanders sees upcoming Midweste primaries as a crucial opportunity to slow her momentum by highlighting his trade policies.

“Geographically, we’re looking good,” Sanders said Sunday on ABC’s “This Week.” “We have a path.”

Sanders acknowledged his campaign has yet to coect with African-American voters, which hurt him badly in his South Carolina loss last month to Clinton.

However, he argued his insurgent campaign is making headway among young black voters.

“I think you’re going to see those numbers change,” Sanders told ABC.

The Associated Press contributed to this report.