Incumbents don't lose when their party has been in power only one term. Carter in 1980 is the only failure in that scenario since 1896. I posted during the 2008 campaign that it was essentially a 2-for-1 if we prevailed.
Four years later, voters aren't tired of the party in charge and they well remember all the faults of the other side. It's natural benefit of a doubt to the incumbent.
I'm always amazed that situational influence isn't allowed more weight. I guess it's more satisfying to obsess over one spur of the moment variable after another as opposed to declaring the foundation was in place years ago.
Granted, the unemployment rate and economic indicators were potential land mines. Obama needed an approval rating near 50% and he wouldn't get there unless the fundamentals cooperated. Once the right track/wrong track ratio quietly showed signs of recovery, with right track finally edging into the 40s, I was very confident. In late 2008 that right track number was below 15%.
I've got to say it was hilarious on sports sites as one right wing SAM (Simplistic Angry Male) after another was certain that this would be 1980 again and Obama would be crushed. They still believed it on election eve, never impressed with the devastating fact that whites were 90% of the voters in Reagan's era and certain to be either 72 or 73% this time. It wound up 72%.
The GOP runs midterm messaging regardless of the cycle. That's more situational ignorance. They get away with it in midterms because single women don't show up and the female vote is only 51% of the total. In general elections that percentage is normally 53 or 53.5, and apparently it moved to 54 this year.