I can see some people thinking that, but Obama, by last year's election, was such a polarizing figure in comparison to 2008 that there seemed intuitively more motivation among the general public to vote against him and benefit by getting him out of office. I believe that the TV ratings for the presidential debates in 2012 surpassed that of 2008, the number of eligible voters increased with the general population increase, the size of the crowds drawn by the Romney campaign in comparison to McCain in '08 (albeit Romney wasn't the ideal GOP candidate in the opinion of many) were larger, and there were historically long lines of voters at polling places reported around the country. These were indicators of a larger total turnout, with Romney the likely beneficiary. Turned out that the reported vote counts weren't consistent with these observations.
So the question is why. One of the possible explanations is massive fraud and cheating in the electoral process, on an unprecedented scale, including hacking into electronic voting equipment so as to alter objective vote counts (which is technically doable). This could have both increased the reported Obama popular vote and decreased the reported Romney popular vote, and could have been decisive in several swing states.
The reason is very simple ~ REDISTRICTING.
It always takes at least one election after redistricting to figure out which precincts have to be beefed up, or consolidated, or moved!
When that first election is a Presidential election people notice. When it's just a mid-term election, there's such a steep drop-off in interest, and voting, no one in particular cares ~ other than the folks responsible for setting up polling stations ~ they fix problems before the next election.
I must be getting old to know that piece off wisdom and to have so many politicians and newsies running off at the mouth imagining that a line of voters means anything at all.
It doesn't!.