By Todd Ruger

Public sector unions got a win Tuesday at the Supreme Court in a major labor case, allowing them to continue to collect fees from nonmembers and, ultimately, have more money for campaign donations.

The shorthanded Supreme Court tied 4-4, a result that affirms a lower court ruling that continued to allow unions to require dues from workers they must represent but who aren’t members. The court issued a one-line order without elaboration that won’t settle the issue nationwide and doesn’t foreclose a challenge on the same issue in the future.

It is the second case where the equally divided Supreme Court was unable to resolve a dispute since the death of Antonin Scalia in February. It is the first major instance where the absence of Scalia, a consistently conservative justice, almost certainly changed the outcome.

The attorney for the challengers, Michael Carvin, said the result “was not entirely unexpected after Justice Scalia’s passing” and suggested they will try to keep the case alive.

“We’ll be filing a petition for rehearing,” Carvin said. “We hope the court will hold it over until the vacancy is filled and the full court can resolve this important issue.”

The president of the California Teachers Association, the union where the challenge originated, and other leaders of public sector unions said Tuesday the case shows the stakes for the 2016 election couldn’t be higher for labor.

“The Supreme Court today rejected a political ploy by the wealthy corporate special interests backing this case to make it harder for working families and the middle class to come together, speak up and get ahead,” said CTA President Eric C. Heins.

Prior to Scalia’s death, legal experts expected the challengers to prevail over the unions in an effort to overturn the court’s 1977 ruling in Abood v. Detroit Board of Education. That decision has allowed unions to avoid so-called “free rider” public employees who get the benefits of the union’s work without paying any dues.

The attorneys for CTA argued to the justices that more free riders would mean less money for its core functions of collective bargaining. Outside experts said that would mean less money for campaign donations because unions would have to shift remaining funds to the costs of bargaining for all members — and that would overwhelmingly hurt Democratic candidates and the party who are backed by labor groups.

At oral arguments in January, Scalia and the justices most likely to sway the outcome of the case sounded unreceptive to the union argument that the current state of the law is fair. Scalia expressed skepticism at that time that unions would collapse if the required union fees ended.

“Federal employee unions do not charge agency fees to nonmembers, and they seem to survive; indeed, they prosper,” Scalia said during the oral arguments. “Why is California different?”

The liberal justices at the oral arguments had cautioned against overturning 40 years of precedent, questioning whether there is a great reason to undo the previous ruling from 1977. Respect for prior rulings, called stare decisis, is a principle of American courts.

The conservative wing of the court already had shown a willingness to overturn the Abood case, as illustrated in the 2014 decision in Harris v. Quinn that found home-care workers in Illinois can’t be forced to pay union dues. The majority opinion in that 5-4 case, written by Justice Samuel A. Alito Jr., called the legal reasoning behind that 1977 ruling “questionable on several grounds.”

The case decided Tuesday, Friedrichs v. California Teachers Association, Docket No. 14-915, was closely watched. Dozens of legal, union, teacher and government groups filing amicus briefs.

Elizabeth Wydra, president of the Constitutional Accountability Center that filed a brief in the case on behalf of 48 current and former Republican state lawmakers and members of Congress, said Tuesday the decision was what they had argued for but highlights the harm of the lingering vacancy on the bench.

“Such an outcome only emphasizes the importance of a court that can operate with a full complement of nine justices that can resolve important legal questions from lower courts once and for all,” Wydra said in a written statement.

Less money for unions’ political activities would overwhelmingly hurt Democratic candidates and the party’s committees. A decision that went against the unions could have consequences for this election cycle if it went into effect immediately, experts said.

The Service Employees International Union, which has about 1.9 million members, donated about $25.8 million in the 2012 campaign cycle, the most recent presidential election year data available, according to the non-partisan Center for Responsive Politics. All of it went to Democratic candidates and committees, which made the SEIU the second-largest donor for the party and the fifth highest overall in 2012.

The American Federation of State County Municipal Employees, the nation’s largest union for public employees, gave $13.4 million in the 2012 cycle, all to Democratic candidates and committees. The American Federation of Teachers gave $10.2 million, all to Democratic candidates and committees.