Back in December, I predicted that Barack Obama's approval ratings could go as high as the low 70s by his inauguration. He didn't quite get there, but his approval is in the low- to mid-60s after a week in office.
With that said, however, Silver's argument that "it is hard to mount a credible argument that Reagan began his term with more political capital than Obama" is bizarre.
Unlike Obama, Reagan unseated a first-term incumbent. He also received more electoral votes and a greater share of the two-party presidential vote than Obama did. The fact that Obama "won a lot more popular votes than Reagan did" and "his margin of victory was larger than Reagan's in absolute (rather than percentage) terms" is an irrelevant consequence of population growth. (By Silver's logic, almost any contemporary election would be considered more decisive than, say, Andrew Jackson's 1832 landslide because of the larger absolute margin in the popular vote.)
Even more importantly, 1980 is one of the three previous contemporary elections that was widely perceived as a mandate election in Washington (along with 1964 and 1994) -- a perception that caused Democrats to change their voting behavior in Congress in the election's aftermath. There's no perception of such a mandate this time around and Republicans are responding accordingly by opposing Obama's stimulus plan. In short, Obama may have a honeymoon in presidential approval, but he doesn't have a mandate.