The headline swing last night was from +4.5 to +8.5 (VA was a Clinton state after all), Terry McAullife was a popular incumbent, Gillespee won among independents, a plurality (40%) said healthcare was their important issue and 80% of them went for Dems, 50% said Trump wasn't a factor in their vote. I'd be a little wary of generalizing from this.
Source: http://www.cnn.com/2017/11/07/politics/2017-elections-exit-polls/index.html
Northren had a slight advantage in the polls and wasn’t expected to smoke him as he did last night, nor were the Dems expected to retake the Va house. This was an asswhoopin’ by any measure. Don’t underestimate the fierce rejection of Trumpism across the country, especially in states with sizeable suburbs.