Willingboro, New Jersey (CNN) Kevin and Wendy Kapuscinski both voted for Rep. Tom MacArthur in November.

Six months later, after their congressman played a central role in resurrecting the GOP's efforts to repeal and replace Obamacare in the House, they sat outside MacArthur's town hall in Southern New Jersey vowing never to do it again.

"He let me down," Kevin Kapuscinski told CNN. "It's a shame."

MacArthur, a second-term Republican congressman, faced off against an explosive crowd Wednesday night in a town hall that stretched more than four hours and left constituents erupting into name calling and shouting.

At multiple points, the crowd serenaded MacArthur with the same song House Democrats sang when Republicans passed their health care bill last week: "Na Na Hey Hey Kiss Him Goodbye."

They waved green fabric into the air when they liked what they heard and raised red fabric when they disagreed.

MacArthur's town hall was a case study. Not only did MacArthur vote for the health care bill, he'd been a key architect of the amendment that got it across the finish line. It was MacArthur who ultimately brought the conservative House Freedom Caucus on board to pass it. And that wasn't lost on his constituents.

"You brought it back from death," one man shouted in a long diatribe that stretched several minutes.

Throughout the night, MacArthur tackled one tough question after another, hearing stories from constituents with an array of health problems from heart defects to mental health issues.

Joanna Robinson, a constituent, asked MacArthur point-blank what would happen to people with opioid addiction.

"I've been clean for two years," Robinson said. "It's not easy staying clean and with the help that I received in Medicaid it kept me clean this long, and I feel for the women and other men who are struggling with this addiction. What's gonna happen to us if you cut this bill? What's gonna happen to our recovery?"

"I want to reassure you that the Medicaid help you've gotten, nothing in this bill is cutting that," MacArthur said.

Throughout the night, MacArthur tried to assure voters that his bill offered adequate protections for people with pre-existing conditions, but constituents struggled to accept his answers.

"My blood will be on your hands," one woman screamed.

Meeting in unfriendly territory

Under MacArthur's amendment, people with pre-existing conditions couldn't be denied coverage, but they could be charged more if they let their coverage lapse and if they live in states that opt out of the protection for people with pre-existing conditions known as community rating.

From the start, the crowd was fired up. As the Pledge of Allegiance came to an end, the crowd repeated the phrase "for all," emphasizing what they viewed as an unfair health care bill. MacArthur also dodged interruptions as he tried to share a personal story about his daughter Gracie, who passed away at 11.

"Shame," someone yelled. "Enough," another shouted. "Write a book," a voice from the crowd said.

"If I talk about my daughter too much, well then so be it," MacArthur said.

He was certainly in unfriendly territory. He won just 12% of the vote in the community back in November. Trump won 9%.

"I came to this town because I want to meet with my constituents and tell you the things that matter to me, the things I' doing and why I'm doing them," MacArthur said. "In this part of the district, there are 40,000 more Democrats than Republicans."

"Props for him for being willing to have that kind of dialogue," said Kevin Mullin, a 21-year-old who added he was opposed to MacArthur.

MacArthur is one of just a handful of Republican members holding town halls during the recess this week during the GOP's first recess since passing the AHCA.

"We're going back in time," said Gail Clark, a 61-year old cancer survivor.

"I voted for him," Clark added. "I crossed party lines and I voted for him."

No call for outside investigation of Trump

Outside the town hall, Democrats organized a rally complete with a blow-up chicken and speeches from constituents who said they'd be adversely affected by the Republicans' plan to repeal and replace Obamacare. One sign outside said: "Greed over people. I have 12 exclusions can I share your insurance Tom?" Another one referenced the ongoing investigations into President Donald Trump's campaign's connections to Russia.

"Putin- Trump: Make Russia Great Again," the sign read.

Penn Reagan, 64 and a Democrat, held a colorful sign that said "Repeal and Replace T-Mac 2018."

"I'm just embarrassed that someone from our state would activate health care again," he said.

While most of the questions at the town hall focused on health care, MacArthur also was grilled about whether supported an independent investigation into the Trump campaign's ties with Russia.

"So Director Comey got fired less than a day ago...my view right now is the FBI still's got some work to do in their investigation and both the Senate and the House Intelligence committees," MacArthur started to say before being heckled by the crowd.

"The answer is no, not yet," MacArthur finally said as the audience booed.