When Labor Secretary Hilda Solis announced her resignation last week, my Washington Examiner colleague Philip Klein quipped on Twitter: "Obama may as well cut to the chase and nominate [AFL-CIO President] Richard Trumka as labor secretary this time."

It's funny because it's true. A Trumka nomination would be about the only way to put somebody more pro-labor than Solis in the position. As far as she was concerned, it was her job to use the federal government to advance Big Labor's interests.

Theoretically, Cabinet secretaries act in the best interest of the nation as a whole. In reality, presidents usually nominate people who share their ideological leanings. Yet even taking that into account, Solis set new standards for bowing and scraping before the interests she was supposedly meant to regulate. She was quite open about it too.

"I am proud and humbled to be your humble servant as labor secretary," Solis said at the 2009 AFL-CIO convention in Pittsburgh. For good measure, Solis also told the convention that then-outgoing AFL-CIO President John Sweeney was her "good friend and colleague" as well as "our president."

Sweeney repaid the compliment by saying Solis was "our sister" and was turning the department into the "Pro-Labor Department."

Solis came by this naturally. She was the daughter of labor activists, her father having been a Teamsters shop steward. Her mother was a member of the United Steelworkers.

Solis was a union stalwart as a member of the California state legislature and as a member of Congress beginning in 2001.

By the time she was picked to be labor secretary in 2008, she had a 97 percent lifetime rating with the AFL-CIO, according to its own congressional voting scorecard.

In his first term, President Obama was unable to deliver what the unions wanted most -- card-check legislation to make workplace organizing drives easier. But Solis, a major cheerleader for that legislation, delivered in other areas.

She stepped up investigations of worker complaints about backpay, recovering almost $280 million for 300,000 workers in 2011 alone. She also pushed to broaden requirements for businesses to disclose the labor law consultants they hire. (This regulation is still pending.) Previously, public disclosure was only required when the consultants also talked to employees. Now, any lawyer whom management hires will have his contract made public. This will likely drive many out of the business altogether. Which will suit unions just fine.

On the other hand, Solis rolled back transparency regulations put in place by the Bush administration to uncover fraud and embezzlement by union officials. The Federal Register announcement actually said the rollback was "to avoid overburdening unions and their officials with unnecessary reporting requirements."

The Labor Department investigations in this area during the Bush administration recovered $93 million of stolen dues on behalf of individual union members. The department reported to me this week that under Solis, the conviction rate has remained fairly steady but recoveries had come to only $17.6 million through 2011 (the last year for which data were available). In other words, the average recovery of these dues is now half what it was under Bush.

Solis also used her office as a bully pulpit for Big Labor. At a Democratic National Committee in February 2011 she pledged solidarity with "our brothers and sisters in public employee unions" who were "under assault" by Wisconsin Gov. Scott Walker and others.

A week later, she told the Communication Workers of America in a conference call: "I am so inspired and proud of all of you, especially those who went down to Wisconsin and also around the country."

She was a dutiful supporter of the president too. In her farewell message to Labor Department staff, she said one of their greatest achievements was "crafting regulatory actions to implement key aspects of the Affordable Care Act," aka Obamacare.

Partisanship in federal Cabinet positions is nothing new or surprising. But Solis set new standards for turning the Labor Department into an entity that coddles Obama's allies in organized labor far more vigorously than it regulates them. In that, Obama will have a hard time finding a replacement for her.

Sean Higgins (shiggins@washingtonexaminer.com) is a senior editorial writer for The Washington Examiner. Follow him on Twitter at @seanghiggins.