I think this is the most important detail that will probably be mostly ignored by the media. Hat tip to Andrew for mentioning it at his blog.
The raw information is at the Daily Kos: among the general Democrat debacle the Progressive Democrats (liberals, in Europe they'd be socialists I guess) hold in almost all their districts, while the so-called blue dogs (conservative democrats, in Europe they'd be called liberals) and New Dems (Blairites?) lose almost everywhere.
This seems to demonstrate that the best way to challenge a tory is not with another tory but with a socialist. It also seems to demonstrate that wherever the Democratic Party presented left-leaning candidates, its electorate did not desert it, but where they run with candidates that looked almost like their oponents, their voters could not be bothered.
I'd dare say it is a show of intelligence by the progressive majority that supported Obama in 2008, no matter how illusory and short-lived was the phenomenon, and leaves room for hope in the US political scenario. The message I'm getting at least is that the left feels clearly lefty and wants left wing policies, not compromises with the right such as keeping Bushites in the government, ratifying the state of emergency decreed by Bush, not closing the Guantanamo concentration camp or, worst of all, covering up BP in its chemical genocide of the citizens and environment of the Gulf of Mexico area.
Anyhow, I'd like to read opinions from the USA: I'm just a watcher from the distance after all. But I think that these results speak well of a sector, the most conscious sector of US society. I really agree: whether the Democratic Party wins or loses is not the matter, what matters is what policies are being implemented, and mostly Obama has been almost impossible to take apart from his infamous predecessor, so it's not like he deserved to win at all.