Media Matters for America says it is a "myth" that having a union hurts a business. In a March article on myths and facts regarding unions, the liberal nonprofit group said that they "increase productivity [and] do not reduce business competitiveness."

But does Media Matters itself really believe that? Apparently not. In early April, it rejected Service Employees International Union Local 500 when it claimed it had -- through a "Card Check" election -- the backing of a majority of the nonprofit's staff.

With that, the nonprofit became the latest in a long line of liberal leaders who espouse a pro-union line but sing a different tune when it comes to their own organizations.

Local 500 was forced to call on the federal National Labor Relations Board last month in an effort to get a vote. The case is still pending. Meanwhile, Media Matters hired Perkins Coie, a law firm that specializes in representing management in labor disputes.

Media Matters spokeswoman Jess Levin told Politico it was just trying to "ensure that we comply with all necessary laws and procedures."

That's disingenuous. Nothing in the law prevents an employer from opting to sit down with a union and work out a contract without getting the feds involved. Media Matters chose not to.

A workers group calling themselves the “Media Matters Organizing Committee” issued a statement last week that they “feel betrayed” by MMFA's stance.

“The actions of Media Matters executives have placed employees in the impossible position of continuing to produce content espousing pro-labor values for an employer who is challenging our right to unionize,” the workers said.

They are at least not alone in the world of liberal advocacy. Organizers trying to represent workers at MSNBC have been similarly frustrated.

While the liberal cable channel's hosts are reliable pro-union advocates, parent company NBCUniversal has not worked out a contract with the National Association of Broadcast Employees and Technicians despite it winning recognition in 2006. In a ruling last month, the NLRB told NBCUniversal to stop resisting and sit down with the union.

Meanwhile, Peacock Productions, an NBC subsidiary, is fighting an organizing bid by the Writers Guild of America, East.

True, the real resistance is coming from NBC's corporate leadership, not the various cable hosts. But when the AFL-CIO tried to enlist those hosts last December, they stayed silent.

In a public letter addressed to Rachel Maddow, Ed Schultz, Al Sharpton, Chris Hayes and Lawrence O'Donnell, AFL-CIO President Richard Trumka called on them to meet with pro-union workers.

“We hope that you heed this call to help these brave men and women appeal to Peacock and to NBC to cease their anti-union tactics. Meet with them, talk to them, call your viewers to action," Trumka wrote.

Only Chris Hayes actually met with the workers, according to a report in Salon. The meeting was kept private and Hayes has apparently never publicly discussed it.

Ed Schultz, perhaps MSNBC's most aggressive pro-union host, reacted angrily when liberal writer Mike Elk called into his radio show to ask if he would support the organizing effort. The NBC host accused Elk of "income envy."

This type of stuff isn't new on the left. Some unions like the Teamsters have fought efforts to let their own staff have unions. So did ice cream makers Ben & Jerry's. Even somebody as anti-business as Ralph Nader has fought unions. He prevented an effort by Public Citizen staffers in 1984.

"I don't think there is a role for unions in small nonprofit 'cause' organizations any more than ... within a monastery or within a union," Nader told the Washington Post.

Funny how liberal leaders only come to this realization when it involves their own organization.