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? …

If the Obama campaign really beat Romney that badly, you’d expect the battleground states to be “higher” on the vertical axis than the other states. That is, you’d expect them to stand out as states where Obama did better relative to 2008. But that’s not really true. He lost 2.05 points in the battleground states relative to 2008 and 2.24 points in the other states—a difference of less than two-tenths of one percentage point (0.19). A simple regression model confirms that, once you’ve taken Obama’s 2008 margin into account, his 2012 margin was no better or worse in the battleground states compared to the other states.