Brad DeLong does the underlying math:
One way to look at last night’s election is that the implicit gerrymandering of the Senate and the in-the-tank-ness of the press corps are keeping people from realizing how big the blowout was. Consider this: it looks like 32,100 thousand Americans voted for Democratic Senatorial candidates, and only 24,524 thousand Americans voted for Republican Senatorial candidates. That’s a 13.4% margin of Democratic victory.
Update:
Democratic senate votes/Republican senate votes:
2002: 21,428,784/18,665,605
2004: 37,645,909/38,164,089
2006: 32,100,000/24,524,000
Total: 91,174,693/81,353,694