From Texas Political Almanac
Going into 2012, the biggest unanswered question was how much the electorate would resemble that of the 2008 "wave election" that culminated in the Democratic Party's sweep at the federal level. By the time the question was answered, the result would show that 2012 was very much a continuation of the demographic tide that swept Obama into office four years earlier. While Obama's overall performance among voters decreased, the share of non-white voters grew.
Throughout the course of the campaign, polling showed a fairly consistent lead for Obama, with some tightening after Obama's lethargic performance in the first televised debate with GOP nominee Mitt Romney. This came despite an uncertain economy and anti-Obama enthusiasm among Republican voters still evident. Given the uncertainty over past Presidential performance in times of high unemployment, the paradox of Obama's political popularity as evidenced in polling led to an inordinate amount of commentary of polling being "skewed" against Romney. The other side of this was the rise in online polling aggregators such as Pollster, Real Clear Politics, and Nate Silver who tended to second the notion of Obama leading in the polls. Nate Silver proved to be the biggest target, ultimately proving his findings correct.
Democrats also gained seats in the United States Senate and House of Representatives. Throughout the United States, Democrats running for the House earned more votes than their Republican counterparts despite Republicans winning 234 seats to the Democrats' 201.