But while unions adopted by a majority of employees can bargain over benefits and pay, those comprised of contractors cannot.

“They can unionize, but they cannot, if they’re properly characterized as independent contractors, bargain for wages and conditions of employment,” said William Gould, professor of law emeritus at Stanford Law School and a former chairman of the National Labor Relations Board.

“Those who are classified properly as independent contractors, if they bargained on wages as a condition of employment, they would be engaged in a conspiracy to restrain trade unlawfully within the meaning of the antitrust laws,” Gould said.

There are potentially other ways under the law for contractors to collectively bargain over wages, Gould said, including if a state passed a law allowing them to do so. But with that unlikely in the near future, a union of, for now, contract workers can wield other powers.

“They could speak out politically. They could fund litigation designed to improve their conditions,” Gould said. “They can try to get legislators elected who are sympathetic to them.”

Ultimately, that issue could find its way to the highest court in the land, Gould said.