In spring 2016, Chris Rabb won a hotly contested Democratic primary for a state House seat in Philadelphia.

While Rabb had a guaranteed spot on the general election ballot as a Democrat — all but ensuring his win in the commonwealth’s largest city — the progressive Working Families Party also wanted to nominate him as its candidate.

The problem? Pennsylvania law explicitly prohibits electoral fusion, a practice that allows multiple parties to nominate the same candidate for the same office in an election. The candidate’s votes are then pooled.

Rabb and the party went to court to challenge the prohibition. They suffered a final loss Wednesday, as the state Supreme Court ruled against them 4-3.

Electoral fusion is legal in just a handful of states, including New York. But it was once the law of the land in most of the U.S., including Pennsylvania.

Attorneys for Rabb and the Working Families Party argued to the Pa. Supreme Court that the prohibition on fusion violates the free and equal elections clause of the state Constitution, since some parties cannot nominate the candidate of their choice.

In a ruling issued Wednesday, Justice Sally Mundy rejected the “argument that the protections afforded by the Pennsylvania Constitution for speech and associational rights require a different result.”

“Here, Appellants and like-minded members of the Working Families Party were able to meet and decide that the candidate who best represented their values was Rabb,” Mundy wrote for the majority. “They then had to opportunity to participate fully in the political process, culminating in casting their votes for the candidate of their choice. Under these circumstances, their speech and associational rights were not violated.”

Rabb said he was “disappointed but not entirely surprised” by the result.

“I philosophically oppose political duopolies,” he said Wednesday by phone. “Part of what I was fighting for was an opportunity for voters to make a protest vote that did not necessitate a spoiler vote.”

“That’s the power and potential of fusion balloting,” he added.

Two justices filed separate opinions dissenting with the majority. Justice David Wecht argued “that the anti-fusion provisions of the Election Code substantially burden fundamental constitutional rights in ways that are not outweighed by the government interests at stake.”

“It is not enough to rely upon facial equality to justify overlooking practical impediments that disproportionately affect smaller parties to the clear benefit of major parties,” he wrote.

Rabb said that fusion balloting would also give candidates a better idea of why they won (or lost), since “they know the distinction between a majority party and a minority party like Working Families correlates with different priorities and complementary values.”

While being a Democrat means many things to many voters, he said, casting a ballot for a third-party like Working Families sends a more specific message about a person’s beliefs — and what they want from an elected official.

Even with the court loss, Pennsylvania could — theoretically — return to electoral fusion through General Assembly action.

“It could happen with the right types of public servants who are elected who value participatory democracy over political duopoly,” Rabb said. “There’s not a big enough proportion of the Pennsylvania General Assembly to make that happen right now.”

Rabb said part of that is ignorance, since many voters and lawmakers don’t even know what electoral fusion is.

He plans to continue fighting for electoral fusion, noting that many court cases that have affected him personally as an African-American man on issues like segregation take time and feature stumbling blocks.

“We can educate,” he said. “We can change people’s minds.”