Prof. Krugman, on why vituperative partisan fights are good things:

I like to remind people who long for bipartisanship that FDR's drive to create Social Security was as divisive as Bush's attempt to dismantle it. And we got Social Security because FDR wasn't afraid of division. In his great Madison Square Garden speech, he declared of the forces of "organized money": "Never before in all our history have these forces been so united against one candidate as they stand today. They are unanimous in their hate for me—and I welcome their hatred."

There are several things worth noting about the above passage. First, it can hardly be said that President Bush's weak and ineffectual attempt to privatize Social Security in 2005 was "divisive," since it quickly collapsed for non-support, even within his own party. It hardly seems like a good endorsement of the strategy when the best example you can come up with for avoiding bipartisan solutions is a policy proposal that was defeated so easily.

Second, FDR could afford a bitter partisan battle when he proposed the Social Security Act of 1935; his party controlled both houses of Congress by overwhelming margins (319-102 in the House, and 69-25 in the Senate), and the measure passed with little opposition (372-33 in the House, and 77-6 in the Senate). No matter who the next President is, he will not likely have majorities even half that large in the Congress, or come close to having enough votes to invoke cloture in the Senate, for that matter.

Lastly, the MSG speech cited above was not from the "divisive" Social Security debate in 1935, but from his reelection campaign the following year. Selectively omitted in the Salon Slate column was this Obamaesque passage towards the end:

Aside from this phase of it, I prefer to remember this campaign not as bitter but only as hard-fought. There should be no bitterness or hate where the sole thought is the welfare of the United States of America. No man can occupy the office of President without realizing that he is President of all the people.

It's always a foolish thing to use FDR as a role model for the use of vicious partisanship. His campaign in 1932 was geared towards blurring distinctions and vague generalities, with the awareness that simply being the principal opponent of Herbert Hoover would be enough to ensure victory. Most of his victories in his first Administration were with Republican support, including the Social Security Act of 1935 (a point that he also alluded to in the MSG speech). Reaching across the aisle to pursue progressive goals was not merely limited to domestic issues; his War Cabinet included several Republicans, including their Vice Presidential nominee from 1936, and he even went so far as to enlist the support of his opponent from 1940, Wendell Willkie, in backing the Lend-Lease Act and related measures in support of America's pre-war build-up.

In short, Roosevelt was a canny politician, willing to take on members of his own party, as well as build coalitions with Republicans and conservatives when it served his purpose. Because of that, when he did go on the offensive against "economic royalists" and the "forces of organized money," he did so knowing he had the backing of the broad center of public opinion. I don't know if Obama is made of similar stuff, but his rhetorical style is certainly not inconsistent with the Father of the New Deal, nor is his belief that excluding half the country from the debate is counter-productive to achieving progressive goals.