First, there was a column by Matthew Yglesias about how much Democrats having been losing at the state level, and why they should be worried about it. This isn't news to me. I don't subscribe to the theory that Dems lose because sometimes voters are just stupid. Dems lose for a variety of reasons, including that sometimes Dems are awful. On the other hand, sometimes Dems win because the GOP is even worse.
However, hoping that your opponent will be even worse isn't a good overall strategy.It's much better to try to be the best candidate you can be, and for the party to try to be the best. Dems haven't been doing this. They've been protecting their own and trying to avoid crazy. Sometimes it's good enough, but often it isn't. So Dems are losing more often.
Yglesias wrote about this two months ago. The effect? A ripple and then nothing. But that is what he expected: "But the truly striking thing is how close to bottom the party is already and how blind it seems to be to that fact." I'll let you know when I see the signs that the Dems are waking up. So far, they're still in deep slumber.
Extra. An example of turning to the GOP because Dems won't do what's necessary.