Could Scott Walker’s Legal Victory Expand PAC Superpowers?

Dan Backer, the conservative attorney who helped bring the 2014 McCutcheon case in which the Supreme Court removed aggregate limits on direct contributions, said he expects challenges to coordination limits in other states.

"Challenges take time and money, but they are coming," he said. "State laws are far more susceptible to challenge on constitutional grounds, largely because of the way in which they are written ... it's rare to have a well-developed state law regulating speech that is thoughtfully constructed with the Constitution in mind and not overly broad."

Before the Wisconsin court ruled in the Walker case, the Wisconsin Club for Growth and its director asked the U.S. high court to shut down the state investigation on constitutional grounds. The court declined to take the case, which may signal its reluctance to review the Wisconsin decision.

If the special prosecutor does try to take the matter to the Supreme Court, it's possible his appeal would focus solely on the alleged conflicts of interest of some of the Wisconsin justices, which would make it difficult for the Supreme Court to weigh in on the free speech issues.

Read more at ProPublica.