A president facing this situation needs to know what's temporary and what's permanent, if only because of the tendency for the one to become the other. Urgent measures are liable to stick around long after the precipitating emergency is passed. There aren't many American homes left without electricity, but we retain a renamed version of the Rural Electrification Administration, a program created by Franklin Roosevelt as part of the New Deal. The Tennessee Valley Authority, created in 1933 to modernize a region of the country still afflicted by malaria, remains with us as well. Expanding government is easy, shrinking it nearly impossible.

On the broader question of what Washington should and shouldn't do, Obama remains hard to read. He inclines simultaneously toward activist government and limited government, which is a tension, though not a contradiction. He favors universal health coverage, but without government taking direct responsibility for it. He is poised to propose cutbacks in our most expensive entitlement programs, Social Security and Medicare, to ensure their survival. Language elsewhere in his Inaugural Address suggests that he sees government as a guarantor of opportunity rather than a provider of benefits, more Clinton's way than LBJ's.

But as he navigates the crisis, Obama would do well to figure out what he thinks about the fundamental question of government's responsibilities. He might begin by pondering some words of his role model, Abraham Lincoln, who in 1854 wrote, "The legitimate object of government is to do for the people what needs to be done, but which they can not, by individual effort, do at all, or do so well, for themselves." Obama's test of practicality comes after Lincoln's test of principle.

Weisberg is editor in chief of the Slate Group and author of “The Bush Tragedy.” A version of this column also appears on Slate.com.

© 2009