I know plenty of people have already said this, but the Senate is an even more impressive story for Democrats than President Obama's reelection last night. Just a few short months ago it was conventional wisdom that Democrats would be lucky if they only lost three seats, and might very well lose enough to turn control over to Republicans. Instead, they gained two seats.
In 2004, I remember being dismayed by Democratic performance in the tossup races. Out of five close Senate races, Republicans won four of them. This year was the exact opposite. Democrats won every single close contest but one (Heller in Nevada), and in the end most of the races didn't even turn out to be all that close. Heidi Heitkamp won by one point; Tester by four; Kaine by five; Baldwin by six; Donnelly by six; Warren by seven; and McCaskill by 16 (!). That's just a helluva performance.
Republicans could have at least retained their current numbers if they'd had the good sense to reject tea party nutballs in Missouri and Indiana, but even if they had they still would have underperformed expectations substantially. Obama's victory wasn't a surprise to anyone living outside the Fox News bubble, but the results of the Senate races constituted a pretty serious, pretty pointed rejection of Republican ideology in red states and blue states alike.