But what about the next four years? Doesn’t Obama still need a governing plan? Sure. And if Obama has been relatively silent lately on some urgent issues—chief among them, climate change—he’s been quite clear when it comes to economic policy. He’s produced plans for strengthening the recovery. He’s laid out principles for reducing the deficit: Relatively modest reductions in spending coupled with higher taxes on the wealthy. And with the coming debate over the spending sequester and expiration of the Bush tax cuts, both set for January 2013, Obama will get a chance to apply those principles.

The stakes in this fight are large: Depending on the terms, they will define the scope of the federal government for at least a generation to come. And, unlike in recent fiscal debates, Obama should have leverage—more, perhaps, than at any time since the earliest days of his presidency. He can hold out in the debate over the sequester and Bush tax cuts, because the default action—doing nothing—is far worse for Republicans than it is for him. And with the newly elected Tammy Baldwin and Elizabeth Warren joining the reelected Sherrod Brown and Sheldon Whitehouse in the Senate, Obama should have a more unified and incrementally more liberal congressional party behind him. (Hopefully they will push Obama, even as they get his back.)

How this plays out depends a great deal on the Republicans, of course. At least since early 2010, after the bruising fight over health care, Obama has been predicting that the Republicans would not become a responsible governing party until they experienced the consequences of extremism. Now that has happened. Republicans effectively ceded winnable Senate seats by nominating far-right candidates. And they lost a potentially winnable presidential election by nominating a candidate who ran on the Paul Ryan budget and even named Ryan as his running mate.

Maybe some moderates will react to Tuesday’s GOP debacle by breaking with the Tea Party, and reaching out to Obama. Or maybe they will be too scared of reprisals from the right wing, as they have ever since Obama took office. I have no idea. But, whatever happens over the next four years, Obama’s reelection guarantees that the laws passed during his first term stay on the books. That instantly makes him one of the most accomplished presidents of modern times. Already Obama and his allies have shaped this country in ways that will last for generations—making life more secure, and creating new opportunities, for tens of millions of Americans.