WILLINGBORO -- That didn't take long.

The first questioner at Rep. Tom MacArthur's town hall meeting here Wednesday wanted to know about those who have pre-existing conditions.

"What will happen to them?" asked C. Andre Daniels, mayor of Westampton Township. "That's what everybody wants an answer to."

To boos and heckles, MacArthur said that 7 percent of Americans, the ones who buy coverage on the exchanges set up by the Affordable Care Act, are facing "an insurance market that is collapsing," and the House Republicans' American Health Care Act was designed to fix that.

For the first part of the town hall, which lasted close to five hours, the audience didn't wait for MacArthur to finish a sentence before shouting at him.

"Some of you tonight have very strong opinions about what you think," MacArthur said.

The meeting was MacArthur's first since he played a key role in saving the House GOP bill that the Congressional Budget Office said would leave 24 million more Americans without health insurance than under the health care law that the legislation repealed and replaced.

"This is your health care bill," said Derek Reichenbecher, a teacher from Point Pleasant. "It was dead in the water. It would have stayed dead in the water but it was the MacArthur amendment that brought this thing forward."

Reichenbecher said he had a heart condition and worried about getting insurance if he lost his job.

"I don't know what happens," he said. "This is something that's very real. This is my life."

MacArthur said that if the Affordable Care Act failed, he couldn't get coverage from the insurance exchanges.

"This is an attempt to fix that very issue," MacArthur said.

Allan Rosenthal, an investment banker from Columbus, criticized the House Republicans' Rose Garden celebration after they passed the bill. MacArthur spoke there.

"What that message sent to America was terrible," he said.

Every one of the 300 seats was filled inside the John F. Kennedy Center, standees lined the walls, and hundreds more assembled hours earlier to protest MacArthur's actions.

Possibly anticipating a hostile reception, MacArthur's office pointed out in advance that Willingboro's population was 73 percent black and gave MacArthur just 12 percent of its vote last fall.

But the entire district will be affected by his vote, said Ann Vardeman, program director for New Jersey Citizen Action, an advocacy group that helped organize the pre-town hall protest.

"This was a cruel bill, an immoral bill, and this was an unconscionable bill," she said. "His constituents will remember his betrayal."

A former insurance executive, MacArthur paved the way to bill's passage in the House by drafting an amendment allowing states to seek waivers from the federal requirements that insurers offer a specific package of benefits and not charge more to those with pre-existing conditions such as cancer or diabetes.

MacArthur has insisted that Americans with pre-existing conditions still would be protected, an assertion rejected by the American Medical Association. Avalere Health, a Washington research company, which said the GOP legislation would cover just 5 percent of those with pre-existing conditions, or 110,000 individuals. New Jersey alone has 49,000.

The possible loss of protection for pre-existing conditions worries people like Geoff Ginter, a certified medical assistant from Pine Beach, whose wife, Colette, had cancer.

While she is now cancer-free, "every day -- there are no exceptions -- she thinks about it,'' said Ginter, who lives in MacArthur's district. "If I lose my job for any reason, my wife is not going to have any health insurance."

The bill would reduce federal spending on Medicaid, the health care program for the poor, elderly and disabled, by almost $840 billion over 10 years, with the savings going to cut taxes for corporations and wealthy Americans.

In addition, New Jersey and other states that expanded Medicaid would no longer get extra funding for new enrollees after 2019.

The Republican repeal bill would hit MacArthur's district the hardest, according to New Jersey Policy Perspective. The district would see its uninsured population rise by 94 percent, to 70,879 from 36,529, the group said. Overall, 500,000 more New Jerseyans would be without health insurance than under current law.

For those with insurance, the GOP bill's diminished subsidies and its provisions allowing insurers to charge more to older customers would mean a 908 percent premium increase for 60-year-old living in Burlington County and making $20,000 a year, according to the Kaiser Family Foundation. That premium would increase to $9,660 under the GOP bill from $960 under the Affordable Care Act.

House Republicans have insisted that they needed to repeal the Affordable Care Act because it was failing, an assertion rejected by the CBO.

Following the House vote, the Cook Political Report, a Washington-based publication that tracks congressional races, said MacArthur now would have a tougher re-election campaign.

A voter registration table was set up outside, and Candice Brown, executive director of the Burlington County Democratic Committee, said she's heard from six people interested in running against MacArthur next year.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.