The Texas Ethics Commission Wednesday voted to shed more light on the "dark money" in state politics, but its action is almost certain to be challenged in court.

The commission unanimously adopted a new rule requiring political nonprofits to disclose their donors if they spend 25 percent or more of their budget on political activity, or if more than 25 percent of their total contributions are political.

Jack Gullahorn, president and general counsel to the Professional Advocacy Association of Texas, said the rule is likely to face a legal challenge.

"Anything dealing with the ever-changing environment surrounding campaign finance laws is going to be subject to serious scrutiny by the courts," said Gullahorn. 

The Texas Tribune thanks its sponsors. Become one.

Steve Bresnen, a lobbyist and proponent of tougher regulation, declined to comment. 

Joe Nixon, counsel for Empower Texans, one of the organizations the proposed rule would impact, said he suspects it will face challenges — though he would not say whether Empower Texans will file a lawsuit. 

"That decision has not yet been made today,” Nixon said.

Nixon and others have argued that the rule violates free speech.

"They have considerable testimony that the rule was violative of the constitution of the United States in several respects,” Nixon said. "There are very serious First Amendment issues at stake.”

Earlier this month, six Texas Republicans told the commission the proposed rule would overstep its bounds.

The Texas Tribune thanks its sponsors. Become one.

The new rule is similar to a bill that passed the Legislature in 2013, but was vetoed by Texas Gov. Rick Perry, who called it an infringement on the rights of Americans. 

According to opensecrets.org, spending by groups in the United States that do not disclose their donors totaled more than $300 million in 2012. 

Earlier this year, the U.S. Supreme Court struck down a law that limited how much an individual could contribute to a federal candidate. Four years prior, the court struck down another law that limited campaign spending by corporations or unions. In both cases, the court’s ruling said the spending caps were a violation of free speech. 

Get The Brief

Never miss a moment in Texas politics with our daily newsletter.