John Sides questions whether Obama's campaign deserves the credit for his victory:
As I understand the "formidable campaign" narrative, it’s that Obama campaign simply did a lot of things much better than the Romney campaign. If so, then one possible implication is this:
Obama should have done better where the two campaigns went head-to-head, relative to places where neither side was campaigning. That is, even though Obama was expected to lose votes in most states relative to a more favorable year like 2008, he should have done better in the battleground states, relative to non-battleground states, because the battleground states were where his campaign’s hypothesized prowess—in fundraising, messaging, GOTV, etc.—was manifest. So did that happen?
Larry Bartels agrees that in "2012, as in 2008, Obama’s electoral performance was quite consistent with what might have been expected on the basis of political fundamentals." He provides the above chart:
We have lots of distinct but broadly consistent statistical analyses of presidential election outcomes. My own favorite is based on just two factors: the income growth rate in the second and third quarters of the election year and the incumbent party’s tenure in office. The [chart] combines these two factors by relating election outcomes to tenure-adjusted income growth, which simply subtracts 1.29 from the actual income growth rate for each consecutive term (beyond the first) that the incumbent party has held the White House.