"It was difficult to get many people to pay attention to this before the ironworkers case," said State Rep. Ron Miller (R., York), the bill's sponsor. "The attention around that case definitely helped round up the votes we needed."
The decades-old exemption came to Miller's attention in 2012, after a U.S. Chamber of Commerce report cited the provision as one of a handful of state laws across the country that appeared to favor organized labor.
But despite a House Judiciary Committee vote backing Miller's proposal in October, the bill stalled for months.
Critics questioned whether the measure was necessary, saying no arcane law would prevent a court from convicting individuals charged with clearly criminal conduct.
The ironworkers case federal prosecutors unsealed in Philadelphia last month challenged that argument.
Authorities alleged that several top leaders of Ironworkers Local 401 carried out a years-long campaign of extortion, harassment, and arson against contractors who refused to hire the union's members.
One of the men charged - union business agent Edward Sweeney - had successfully used the state's labor carve-out to defend himself against stalking and harassment charges in Philadelphia Municipal Court three months before his arrest in the federal case.
The victim in that case was a Post Bros. executive whose company had been sparring with Local 401 over construction of an apartment complex near 12th and Vine Streets.
She testified in November that Sweeney had cornered her at a nearby cafe, cursed at her, and backed her against a counter. Later in the day, she said, he approached her with his hand shaped like a gun and mouthed, "Bang, bang, bang."
Pennsylvania AFL-CIO president Richard Bloomingdale said Wednesday that no one would defend Sweeney's alleged acts in either the state or federal case. Still, Bloomingdale and other labor leaders vowed to continue their fight against Miller's bill.
"When somebody's job is threatened and their livelihood, people do stupid things on both sides," he said. "We just feel like this bill is going to be used to keep people from having a voice at work."
With Wednesday's House approval, the bill now moves to the Senate. No date has been set for its consideration there.