The ad attacks MacArthur over his role as the founder and leader of York Risk Services Group, an insurance industry firm that was accused in three instances of shortchanging policyholders after wildfires or hurricanes.
The ad touches on a wrenching issue for many in the district, which was pummeled in 2012 by Hurricane Sandy, and is still recovering amid complaints of delays and insurance hassles. The spot opens with an overhead view of the Jet Star roller coaster stranded in the ocean, an iconic image of Sandy's wreckage.
"When disaster strikes, some try and help. Insurance CEO Tom MacArthur tried to profit," the ad intones, over grainy images of fires, waves and MacArthur.
MacArthur called the ad "repulsive" and demanded that Belgard disavow it. His campaign pointed out that he had been out of the insurance business for years by the time Sandy struck, and he had no role in handling claims from the disaster, while adding that Belgard had spent years as a lawyer working for insurance companies.
"Trying to directly link me to the devastation of Hurricane Sandy is a disgusting tactic that has no basis in truth," MacArthur said in a statement. "Belgard should be ashamed."
The ad will bring to voters' living rooms sparring that has been building for weeks and seems sure to intensify as the election nears and Democrats' hopes narrow, both nationally and in the Philadelphia area, where races that were expected to be competitive in Chester, Bucks and Atlantic Counties seem to be tilting toward Republicans.
The attacks on MacArthur revive an issue he first faced in the Republican primary race against Steve Lonegan.
He readied himself: In recent weeks his campaign circulated a memo highlighting Belgard's past work as an insurance adjuster and 16 years as a lawyer for a firm, Sweeney & Sheehan, that defends insurance companies.
"Aimee Belgard either has a convenient case of amnesia, or she is just plain dishonest," MacArthur wrote in the memo.
The Belgard campaign scoffed at MacArthur's comparison.
"The fact that Tom MacArthur thinks that Aimee's employment as an attorney somehow compares to the way he made his fortune as the president and CEO of a company known for delaying and denying claims to disaster victims only proves how out of touch he is with hardworking middle-class families," Belgard spokeswoman Hannah Ledford said. "He was in charge."
The ad is one of the first two the Democratic Congressional Campaign Committee launched for the midterm general elections and was set to be shown on cable in the district starting Tuesday. The other is in New York.
At stake in South Jersey is a seat where Republicans for decades have won congressional races - with one recent exception, 2008 - but where there are enough swing voters that President Obama won twice. The open seat makes the race appear more competitive.
Democrats have reserved $1.3 million of airtime in the South Jersey district, but a spokesman would not say how much is being spent on this first spot.
In the GOP primary, MacArthur faced attacks over the work of his former firm in cases in which his company and the insurers it worked for were accused of paying hurricane or fire victims less than they were entitled to.
York and other insurance firms were sued in Texas by the Port of Galveston and Houston Baptist University after Hurricane Ike struck in 2008. York was an adjuster for the insurers.
California regulators also cited York and one of its clients in 2012 for allegedly mishandling claims arising from a 2008 fire that ravaged a mobile-home community.
Each case was settled without any admission of wrongdoing. MacArthur left York in late 2010, before the settlements in the cases of the port and wildfires. He sold it for around $500 million.
The Port of Galveston received the $15 million its suit sought, according to lawyer for the port. In California, York paid a $142,500 fine and the insurers paid victims an additional $11 million in claims.
Officials at Houston Baptist declined to comment when The Inquirer contacted them earlier this year.
MacArthur's campaign said the settlements were finalized after he had left the company.
Lawsuits are common in the insurance sector, the campaign said Tuesday, and York was involved in a "relative handful" among the more than a million claims it handled under MacArthur's leadership.