Are unions desperate? When it comes to reviving their fortunes in the private sector, it certainly seems that way. Union leaders, unable to reverse decades of continued decline in private sector membership, are seeking political solutions to their ills — specifically, changes to labor law that would favor unionization.

They pinned their hopes on the election of Barack Obama as President, following the Democrats’ winning control of Congress in 2006. With Democrats running both elected branches of the federal government, pro-union legislation — including “card check” and bailouts for underfunded union pensions — seemed imminent in the early days of the Obama administration.

However, effective Republican opposition managed to hold back much of the unions’ legislative agenda. Then the Democrats’ trouncing in the 2010 midterm elections ended union hopes of pro-union labor law changes in Congress. Yet despite that huge setback, unions haven’t given up on politics, and instead have moved on to a different arena.

Obama will need organized labor’s support for his reelection campaign, so it’s in his self-interest to stay on the unions’ good side. This may explain why his administration has been pushing unionization through regulation — enacting regulatory changes favoring unionization without the consent of Congress. Considering the lengths to which the administration is going, it’s fair to ask: Is Obama desperate to give unions something?

Two key agencies in the administration’s efforts are the National Labor Relations Board (NLRB) and the National Mediation Board (NMB). The NLRB supervises the National Labor Relations Act, which governs labor relations involving most private sector employees, while the NMB does the same for the Railway Labor Act (RLA), which governs railroad and airline employees.

The NLRB recently threatened to sue Boeing for its decision to build a major new plant in South Carolina, a right-to-work state, as well as four states — Arizona, South Carolina, South Dakota, and Utah — for enacting amendments to their constitution that protect a worker’s right to secret ballots in union organizing elections.

The NLRB’s case against Boeing rests on a thin reed. The Board seized on a statement by Boeing Commercial Airplanes CEO Jim Albaugh that an overriding factor in the decision to locate the plant in South Carolina was that the company cannot afford to have a work stoppage “every three years.” The NLRB cited that statement as supposed evidence that Boeing was trying to retaliate against unionized workers in Washington State. In fact, Albaugh was not referring to any specific union job action.

Moreover, the International Association of Machinists and Aerospace Workers, which first filed the complaint against Boeing with the NLRB, had waived having a say on where the company could locate its new facilities. Finally, Boeing wasn’t transferring any work but rather expanding it. The company, facing a backlog for orders of its new 787 Dreamliner passenger jet, had hired 2,000 additional workers at its Puget Sound facilities, even as it hired another 1,000 in South Carolina.

A year ago, the NMB changed RLA voting rules from requiring a union to win a majority of votes in a bargaining unit to be certified as its monopoly bargaining representative to requiring a majority of votes cast — which made it possible for a union to become certified with only a minority of bargaining unit members voting for it. For example, under the new rules, if only 80 workers show up to vote out of a bargaining unit of 100 employees, the union would only need 41 votes to become the legally mandated representative of all workers in the bargaining unit.

Indeed, that has already happened. On November 5, 2010, the Communication Workers of America (CWA) won an election it would have lost under the old rules. (The FAA Reauthorization Bill, passed by the House on April 1, restores the RLA’s original voting rule, but the bill still needs to go through conference committee.)

To call the actions of the NLRB and NMB spurious and arbitrary would be charitable; unwarranted and baseless would be a more apt description. In fact, the NLRB’s and NMB’s actions go so far in promoting organized labor’s agenda that now some Republican lawmakers are pushing back, and looking into the politicization of these agencies.

On May 3, Sen. Mike Enzi (R-Wyo.), minority ranking member of the Senate Health, Education, Labor and Pensions Committee, joined nine other senators in sending a letter to NLRB Acting General Counsel Lafe Solomon requesting documents pertaining to the Board’s actions against Boeing.

Then on May 12, House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.), along with Reps. Trey Gowdy (R-S.C.) and Dennis Ross (R-Fla.), also wrote to Solomon, requesting documents pertaining to its threatened lawsuit against Boeing and the four states with secret ballot amendments — including any communications with union officials.

On May 13, Rep. Tim Walberg (R-Mich.), chairman of the Workforce Protections Subcommittee of the House Education and Workforce Committee, and 10 other senators (including Reps. Gowdy and Ross) also sent Solomon a letter, in which they strongly criticize “what we perceive to be an activist, job-destroying agenda.”

And on May 17, Reps. Issa and Ross wrote to NMB Chairman Harry Hoglander, requesting documents related the NMB’s change of the RLA voting rule — including, as with their request to Solomon, communications with union officials.

The NMB documents sought by the lawmakers are due to House Oversight Committee on May 24 and the NLRB documents on May 27. They should make for an interesting reading.

The GOP pushback is welcome and timely. With pro-union legislation off the table, the Obama administration seems to be throwing every pro-union regulatory initiative at the proverbial wall to see what sticks. For Obama, that may represent his last chance to earn meaningful policy successes for his union supporters. For American businesses struggling to recover, however, it only amounts to yet more regulatory uncertainty and added costs they can ill afford.