A progressive mandate to govern

From Megan McArdle, about Obama's supposed progressive (or to some, socialist) mandate to govern.

If the country is so progressive, how come Bush won the popular vote four years ago? Did all the center right people die? Or are American voters somewhat mercurial? Also, how come Bush had no mandate four years ago? Did the American voter get more mandative? Would John McCain have had a mandate if he'd achieved these kinds of numbers? Or would that be entirely different?

No need to answer. The rest of us already know what the answer is.