On Wednesday, Labor Secretary Hilda Solis announced that she was stepping down. That prompted all sorts of Twitter snark: "we have a secretary of labor??" And so on.

Yes, people, I exist. (Ron Edmonds/Associated Press)

But, yes, the United States does have a secretary of labor! And now is as good a time as any to look back at what the Department of Labor actually does — and how Solis has fared during her time in charge. Here's a rundown of the big, important items:

 — Managing job training and other unemployment programs. The 2009 stimulus bill included $67 billion for unemployment insurance benefits, job training, and other work programs. It was the Department of Labor's job to oversee that money.

So how'd it go? During Solis's tenure, 1.7 million people completed federal job-training programs. Workers in Kansas learned how to pave highways. And so on. But it's still not clear how much good these programs accomplished. Although many economists support job-training programs in theory, it's hard to gauge the effectiveness of the stimulus specifically — few good studies exist yet. Back in 2010, a New York Times investigation found that many retrained workers were still struggling to find work.

— Enforcing wage and hour laws. Shockingly, companies don't always follow the law when it comes to paying workers' wages. That's where the Department of Labor comes in. Solis made a point of reviving this wing of the agency, using stimulus money to hire hundreds of new enforcement officers. "There's a new sheriff in town," she declared in 2009. Last year, the department's wage-and-hour division recovered some $280 million in pay for 300,000 workers, a new record.

Solis generally gets high marks for this: "Under her tenure, there was a particular emphasis on protecting the most vulnerable workers—immigrant workers, teenagers, misclassified workers," says Kate Bronfenbrenner, a labor expert at Cornell. She explains that these workers are most likely to be wrongly classified as independent contractors or shorted on wages because they're either unlikely to speak out or afraid to lose their jobs.

(Ricky Carioti-The Washington Post)

— Enforcing safety regulations. The Labor Department includes both the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). Experts say that the people in charge of these offices can make a big difference to actual workplace conditions. And the consensus is that Solis was far more aggressive than her predecessor during the George W. Bush years, Elaine Chao. For instance, BP got hit with a record $87 million fine for its role in a 2005 refinery explosion.

Not everyone was happy with Solis' record, though. Mine-safety advocates criticized MSHA's failure to enact new rules after the Upper Big Branch coal mine explosion in West Virginia, which killed 29 workers. “What regulatory scheme has grown out of Upper Big Branch that has changed mine safety?” J. Davitt McAteer, a former MSHA director told The Washington Post. “The answer is nothing.”

— Setting up new workplace regulations. The Department of Labor doesn't just carry out enforcement. It also constantly puts forward new rules. That process has long been quite sluggish, and Solis didn't do much to speed it up: A recent investigation by the GAO found that OSHA takes eight years, on average, to issue a new safety rule. That's far slower than most other regulatory agencies.

But in many ways, Solis has been constrained by both the White House and Congress. A key safety rule on silica dust for miners and construction workers has been bottled up in the Office of Management and Budget since 2011. Last year, the department proposed new rules that would have prevented children from performing agricultural work deemed dangerous. But after a fierce blow-back from farm groups and the GOP, the White House backed down, and Solis eventually withdrew the rule altogether.

There's still plenty of work left for the next labor secretary. Under Solis, the department proposed a regulation that would bring 1.8 million home-care workers under federal minimum-wage and overtime rules. That has yet to be finalized. 

— Regulating labor unions. The Department of Labor doesn't just regulate employers. It also regulates labor unions. And on this front, conservatives often criticized Solis for not doing nearly enough to enforce financial disclosure rules for unions. To the contrary, she pushed instead for greater financial disclosure for management consultants.

Frances Perkins, laying down the law

— The bully pulpit. All those things above are crucial, but the Department of Labor is still one of the lesser cabinet agencies. It doesn't have the influence or reach of, say, the Pentagon. So one mark of an effective labor secretary is his or her ability to use the bully pulpit to make labor and workplace issues more visible. "Frances Perkins was able to change the political discourse around labor under FDR," says labor historian Nelson Lichtenstein. "And, to a lesser extent, Robert Reich was able to do that [under Clinton]."

But what about Solis — the first Hispanic woman to head a Cabinet agency? Lichtenstein isn't sure that she ever really managed to break through. Solis earned plenty of press for her early promise to crack down on wage theft. "But since then, we haven't heard much from her," Lichtenstein says. "On the two biggest labor questions of the first term, card-check and Obamacare, as far as I can tell, she wasn't a major player."

So, secretary of labor is an important job. But it's also frequently a controversial one, at least as far as Congress is concerned. House Republicans passed a number of bills last session to block new Department of Labor regulations, and the agency's budget is likely to face pressure in the years ahead. That all means the confirmation hearings for Solis's replacement aren't likely to be entirely peaceful.

Related: Dave Jamieson has a longer look at Solis' constant battles with the White House and Congress.