What is the purpose of the National Labor Relations Board? Is the federal agency meant to be neutral arbiter of labor laws? Or is meant to be an advocate for Big Labor, helping to ensure it organizes the U.S. workforce? Under President Obama, the NLRB has chosen the latter.

That was the only conclusion District Judge Arthur Schwab said he could draw from the "overly broad and unfocused" subpoenas the board's general counsel had submitted in the case NLRB v. University of Pittsburgh Medical Center & UPMC Presbyterian Shadyside.

"The Court has never seen a document request ... of such a massive nature. The Court does not see how these requests have any legitimate relationship or relevance to the underlying alleged unfair labor practices," Schwab said in Friday's ruling. The case involved Service Employees International Union's effort to organize hospital employees.

He said the request "arguably moves the NLRB from its investigatory function and enforcer of federal labor law, to serving as the litigation arm of the Union, and a co-participant in the ongoing organization effort of the Union." He nevertheless granted the request.

An NLRB spokesman declined to comment.

Schwab's ruling was notable for being unusually blunt about the NLRB's direction. Obama has made stocking the board with pro-union appointees a priority of his administration. The case involving UPMC was only the latest example of how this is paying off for Big Labor.

Obama's nominees have included Craig Becker, a former top lawyer with SEIU and the AFL-CIO; Richard Griffin, a former top lawyer with the International Union of Operating Engineers; Sharon Block, a former staffer for the late Sen. Ted Kennedy; and Nancy Schiffer, also a former top AFL-CIO lawyer.

Mark Gaston Pearce, Obama's pick to head the board, said last year: "Our job today, just as it has been since the Great Depression, is to ensure the right of millions of working men and women to organize and bargain collectively."

Under Obama, the board's general counsel leveled an unprecedented complaint against Boeing involving a factory it was building in South Carolina, a right-to-work state. The complaint alleged that an executive's admission that Boeing was opening the factory there partly to avoid future labor conflicts was itself proof of retaliation against its machinists' union. Boeing later settled with the union.

Earlier this year, the NLRB has announced it will issue a new rule speeding up the union election process, hampering the ability of businesses to respond to organizing drives.

It has also expanded earlier precedents allowing so-called "micro-unions" — organizing efforts that do not involve all employees in a workplace, making it easier for unions to gain a foothold there.

Late last month, the NLRB's general counsel gave a major boost to Big Labor's efforts to organize fast-food workers by rewriting franchising law. The counsel announced that the NLRB would treat McDonald's Corp. as the employer for all of its restaurant workers even though 80 percent of the restaurants bearing its name are really privately owned businesses that rent the name. The impact of that ruling is still reverberating across the business world.

Obama's efforts have hit some bumps along the way. He was so eager to get Griffin and Block on the board that he made recess appointments that were ruled unconstitutional in January 2013 by the U.S. Court of Appeals for the D.C. Circuit. A unanimous Supreme Court upheld the ruling in June. That effectively voided a year's worth of NLRB decisions because without those two appointees the board lacked a quorum.

The president's response was to renominate the two. Senate Majority Leader Harry Reid, D-Nev., threatened last year to scrap the filibuster if Republicans didn't give in. The ultimate deal resulted in Griffin and Block being dropped in favor of two other nominees the White House made in consultation with Big Labor: Schiffer and Kent Hirozawa, Pearce's former top counsel. The now fully staffed board is in the process of reaffirming the decisions voided by the Supreme Court.

Oh, and that NLRB general counsel who rewrote franchise laws in the McDonald's case and whose massive subpoenas stunned Judge Schwab? His name is Richard Griffin.