"The Dems seem to be convinced that the demographic shift is complete (in Virginia) and don't have to worry about challenges to their power ever again."
Not by the e-mails I'm getting from the state Democratic Committee. They're nervous as hell that Virginia is still seen as a battle ground state instead of being solidly anti-Trump. And they seem to recognize that they need to walk something of a fine line on the Free *expletive deleted*it policies that they're coming out with. A lot of them have been scaled back from what was originally proposed.
Remember, it was only in 1994/1995 that Virginia flipped from Blue to Red at the state level. Prior to that, the state had been pretty solidly blue since Reconstruction.
There had been Republican three consecutive Republican governors in the early 1970s, but the legislature stayed in the hands of the Democrats. Prior to Linwood Holton, who was elected in 1970, the previous Republican governor was Gilbert Walker... in 1869. And he was initially appointed by the US Army, but was later elected outright.