by Eric Rauchway

Here is a chart (data here) showing Democratic representation in the Congress since the New Deal; the black bar indicates the threshold for a majority. It's way too soon to say anything really meaningful about this, but here are two of my thoughts: 1. You could spin this as a narrow, non-ideological, throw-the-bums out victory. On this read, the Congress would have a definite mandate to

a) pursue investigations of corruption in the administration and its predecessor Congresses,
b) restore limits on executive powers,
c) revive reality-based accounting and fiscal responsibility,

but not necessarily a mandate to legislate left-of-center solutions to, e.g., the ongoing imbroglio that is our national health insurance system. 2. Or you could spin this the other way, and say the Republican majorities from 1994 onward were themselves a throw-the-bums out, nonideological response, artificially prolonged by the politicization of 9/11 and the War on Terror.
On this reading, those majorities had no real mandate to roll back the New Deal. The Republicans seem to believe this reading, actually: recall the immense care with which they talked about rolling back New Deal legislation--they spoke of "saving" Social Security, or "strengthening" it, not of e.g., fundamentally changing its purpose so it's no longer recognizably a New Deal initiative. On the whole, I think there are elements of truth in both readings, but that there's more merit in the second reading than one might at first think. Unlike the New Deal majorities, the new Democratic majority does not rely on the segregationist South (which always hampered efforts at more-liberal legislation), and the newly Democratic Congressmen come from more-liberal areas of the country, who may at long last have realized that if they really wanted more-liberal legislation, they weren't going to get it from Republican Congressmen, however moderate they seemed.