Simple, the Democrat party looks strong, but it is just as badly fractured as ever. There is no real core just a bunch of self-interested groups who will attack each other like jackals when they aren't attacking an external threat. They were unified against a external threat in the Republican party, and they benefited because the economy took a hit.
Now, they are without and external threat as they see it. Which means they will turn on each other in a few months.