This is exactly right:
Not me. Or, rather, I think the evidence suggests that mandate is a meaningless concept. America went to the polls in 2000 and whatever you think of what went down in Florida, clearly more people overall voted for Al Gore than for George W. Bush. What’s more, a substantial minority of people voted for a candidate who thought Gore was insufficiently leftwing. And the exit polling made it clear that Bush had the edge over Gore on a bunch of “character” issues. This series of facts, combined with the regnant ideology of mandate-ism, led a lot of pundits to conclude that Bush would, due to his lack of mandate, curtail his agenda. In fact, he did no such thing. And while that was bad for the country, the lack of a mandate wasn’t a practical problem.
Say what you will about Bush, the one thing he understood is that the only meaning of "mandate" is "whether you have the votes in Congress." And of course the even better example is that FDR -- almost certainly the most transformative president of the 20th century -- ran essentially as more-Hoover-than-Hoover in 1932, which didn't seem to affect his actual governance. For this reason, the number of Democrats in the Senate and the number of progressive Democrats in the House will be much more important to whether health care reform can pass and what form it will take than the precise proposals made by candidates during the Democratic primary.
--Scott Lemieux
