The Obama administration is acting unilaterally to give states more flexibility in designing their welfare programs. This is something Republican and Democratic governors have wanted for some time, and the White House has been clear that they do not intend to permit states to ease up on work requirements -- "“no plan that undercuts the goal of moving people from welfare to work will be considered or approved," says Kathleen Sebelius, the Secretary for Health and Human Services. Nevertheless, as Ramesh Ponnuru writes, it's a major assertion of authority by the executive branch. -- authority that no previous administration has exercised.
I'd add that it's not, by any means, alone. In the absence of congressional action, the White House has also claimed significant authority to issue waivers around the No Child Left Behind law, to regulate carbon emissions through the EPA, to make recess appointments over the objections of the minority. The Federal Reserve has taken a more active role in the economy than it otherwise would have liked to -- as Ben Bernanke said in his June news conference, "We welcome economic support from any other part of the government...cooperation would be great." And recent legislation has featured efforts to devolve future decision making on tough issues to non-congressional bodies, like the Independent Payment Advisory Board that was create in the health-reform law.
The metaphor we tend to use for congressional dysfunction is "gridlock." When you have gridlock, nothing moves. But that's not quite what we've seen. When Congress grinds to a halt, other governmental actors step into the breach. This isn't a particularly good alternative: For one thing, these other actors don't have the powers of Congress, and so they need to use roundabout, inefficient ways of achieving their goals. For another, these actors are less accountable than Congress.
But it's important to realize that this wouldn't happen if Congress didn't want it to: Just as Congress could act to write a climate bill, it could also act to stop the EPA from regulating carbon. But when gridlock is driven by minority obstruction, you often have a majority that would like to see some effort made to address these problems, and if they can't do it themselves, they're willing to stand back and let other parts of the government do it. This is just one more reason why the increasing level of congressional dysfunction should worry those on both the left and the right: It's leading government to work in ways the Founders never intended, and that frankly doesn't make very much sense.