Everyone’s talking about a new New Deal, for obvious reasons. In 2008, as in 1932, a long era of Republican political dominance came to an end in the face of an economic and financial crisis that, in voters’ minds, both discredited the G.O.P.’s free-market ideology and undermined its claims of competence. And for those on the progressive side of the political spectrum, these are hopeful times.

There is, however, another and more disturbing parallel between 2008 and 1932  namely, the emergence of a power vacuum at the height of the crisis. The interregnum of 1932-1933, the long stretch between the election and the actual transfer of power, was disastrous for the U.S. economy, at least in part because the outgoing administration had no credibility, the incoming administration had no authority and the ideological chasm between the two sides was too great to allow concerted action. And the same thing is happening now.

It’s true that the interregnum will be shorter this time: F.D.R. wasn’t inaugurated until March; Barack Obama will move into the White House on Jan. 20. But crises move faster these days.

How much can go wrong in the two months before Mr. Obama takes the oath of office? The answer, unfortunately, is: a lot. Consider how much darker the economic picture has grown since the failure of Lehman Brothers, which took place just over two months ago. And the pace of deterioration seems to be accelerating.