I just read Nate's post The Population and the Popular Vote. It genuinely surprised me about the true extent of the mandate that Obama just received. In terms of the % of the population that voted for Obama, his victory was much more of a landslide than is popularly understood.
As Silver himself put it:
Obama has received at least 68,724,397 popular votes for the Presidency. I say "at least" because they're still counting in California and several other states, and so Obama's total should wind up comfortably over 69 million; 70 million appears unlikely, but is not entirely out of the question.
This total represents 22.62 percent of the Census Bureau's 2008 estimate of United States population, which was 303,824,640. That figure doesn't sound that impressive at first glance -- fewer than one in four Americans actually voted for Barack Obama -- but it's actually the second-highest percentage ever, trailing only Ronald Reagan in 1984:
As Silver notes, such factors as the lowering of the voting age to 18, the abolition of legal impediments to voting, and an aging population have led the % earned by the winning candidate to have increased over time. Even so, however, Obama's obtaining the support of nearly 23% of the population is truly historic. He did better than Nixon did in his 1972 landslide, which also took place after the lowering of the voting age and the enactment of the Voting Rights Act. As Silver notes, he did almost as well as Reagan did in 1984.
Adding this high % of the national population to the major Dem victories in the Senate, the House, and at other levels, Obama has a clear mandate. Anyone who repeats the canard about the US being a "center-right" country is either consciously lying, or they don't know what they're talking about.
The US is clearly a center-left country now, and I hope the Dems govern like it. If W could claim a mandate 4 years ago, Obama can claim an imperative now. There's a popular mobilization here that can clearly be harnessed on our behalf.