"The stars seem aligned in favor of labor organizations for really the first time in over a decade." Steven Bernstein, a labor attorney in Tampa, Florida, who represents management, said in an interview. Employers "should be very anxious."

The board reached full strength last year after a two-year standoff with Republicans who blocked Obama nominees, threatening to leave the five-member panel with too few members for a quorum. Obama nominated two Democrats, including a former general counsel for the United Auto Workers, to serve with Chairman Mark Gaston Pearce, a Democrat who has been on the board since 2010, along with two Republicans.

General Counsel

The makeover was complete in November when Richard Griffin, a former lawyer for the International Union of Operating Engineers, took over as general counsel, a powerful post that oversee investigations and prosecutions and acts independently of the board.

Union advocates say the board is providing the kind of labor-law enforcement it lacked under President George W. Bush.

"It was a cadaver under the Bush administration," Richard Trumka, president of the AFL-CIO federation of 56 unions with 12.5 million members, said in an interview. "It didn't represent workers. It didn't enforce the law."

Critics say Obama is returning a favor to organized labor, a reliable source of donations and grass-roots campaign support for Democrats. Labor groups spent more than $189 million in the 18 months before the 2012 election. Thousands of union volunteers worked in battleground states like Ohio to urge people to vote for Obama and Democrats.

Obama, Labor

"The administration in my personal view was in many ways indebted to organized labor for helping to elect the administration the first time and re-electing them," Bernstein said.

Union membership has been on the decline for decades in the U.S. and last year 11.3 percent of workers were in a union, unchanged from 2012 and down from 11.9 percent in 2010, the Bureau of Labor Statistics reported. Union membership in the private sector last year increased to 6.7 percent from 6.6 percent a year earlier. It was 6.9 percent in 2011 and 2010.

"A new board could come in and change the way the law is applied," Jim Gross, a professor at the Cornell University School of Industrial Labor Relations, said in an interview. "That's not peculiar to a Democratic appointed administration or a Republican appointed administration."

Griffin said he would continue initiatives of his predecessor, including the Pacific Publishing case. He also plans to shore up rights for union workers who aren't rehired after a takeover, and when employers decline to disclose financial information in contract talks.

'Prosecutorial Discretion'

"My job is kind of one of prosecutorial discretion," Griffin said in an interview. The agency, "is in a position to bring before the board changes in the law."

The U.S. Chamber of Commerce, the nation's largest business lobbying group, expects the NLRB also will move soon to make it easier to hold union elections and let union officials communicate with employees through company e-mail. Employer groups are against both proposals.

The board has taken a "decided shift to the left," James Plunkett, director of labor policy for the Washington-based U.S. Chamber of Commerce, said in an interview. "They've been overturning decades of precedent. Sticking their noses into employers policy."

Federal courts could still block the NLRB's agenda — and have. In separate rulings last year, two courts struck down a decision that required all employers to inform workers of their rights to form a union. The board has said it wouldn't appeal.

Recess Appointments

The current board began taking shape last year when a federal court ruled Obama violated the Constitution by naming three NLRB members in 2012 when he said the Senate was in recess. The court disagreed, saying the moves illegally circumvented the Senate's power to advise and consent on nominations. The Obama administration has appealed that decision to the Supreme Court, where a decision is pending.

In the meantime, Obama agreed to Republican demands and replaced the two Democrats he appointed in 2012 with two new Democrats. Both were confirmed by the Senate in July.

The constitutional doubts about the board's decisions in 2012 cast into doubt the legitimacy of several hundred board actions. Employers are bracing for the board to revisit those decisions.

The chamber's Plunkett said the board will probably take up a rule that would speed up worker elections to form a union, denying employers time to respond.

The rule is needed because "employers have overwhelming advantages," Craig Becker, AFL-CIO's general counsel and an NLRB member from March 2010 to January 2012, said in an interview.

Board Quorum

The rule was put in place in 2011 and rescinded on Jan. 22 after a federal court ruled it invalid because the board adopted it without a quorum. With all members confirmed by the Senate, advocates on both sides said the election rule is likely to be revived.

The board also may review a 2007 ruling by President Bush's board that denied employees the right to use company e-mail for other purposes, Griffin said. The case involved communications from a Register-Guard newspaper worker in Eugene, Oregon, who was a union president.

When "employees use e-mail as part of their everyday, day- to-day work, you could make the argument that it's the functional equivalent of water-cooler talk," Griffin said. "There were very strong dissents" in the case.

In the Pacific Publishing case, the board's Seattle office dismissed the union's complaint that the company illegally withdrew union recognition, It found no evidence managers played an improper role in the employees' decision.

Delay Action

The union appealed to Washington and on Dec. 30, the board filed a complaint against Pacific Publishing and said the employer must delay any action for a "reasonable period." During that time, employees may change their minds and their union affiliation would continue.

Peter Bernhard, president of the company, had relied on a law that let him withdraw recognition on the spot.

"I thought there was some sense of fairness to the whole process and this is anything but fair," Bernhard said in an interview. "To go back and retroactively say that we were wrong because we didn't follow rules that weren't even in existence at the time we did what we did is just ridiculous."

The complaint is scheduled to be heard by a labor board judge March 25. Dennis Hayes, who represents the Teamsters union in the case, didn't return a call seeking comment.

Griffin asked critics to judge him by his actions.

"I would hope that they would take the time to review what actions I take as opposed to jumping to conclusion based on some speculation about what they think I might do," Griffin said.