Dems have won 5 out of the last 6 popular votes in presidential elections. President Obama won by a larger percentage in 2012 than President George W. Bush had in his two elections combined. Obama won 9 of 10 swing states. Even if he had lost Ohio and Florida he would have won.
The Dems won 9 out of the 10 close Senate races. 90%. Increasing their majority in the Senate to 55.
The Dems in the house gained several seats and as a whole got more than 1,000,000 more votes than the Republicans did. The only reason the Dems didn't win an outright majority is because of the perfectly legal gerrymandering done by Republican led State Legislative bodies after the 2010 elections.