Warning sign for Democrats: While overall turnout was up 12% from the 2014 gubernatorial primary, the increase was concentrated in only 9 counties, with the counties around the D.C. metropolitan area making up almost all of it. 15 counties saw declines in turnout, including every county on the Eastern Shore. It's similar to what we saw in Virginia with Northam's win heavily on the backs of metropolitan areas. The party's infrastructure in non-metropolitan areas continues to atrophy.
Northam also won by a lot more than Terry McAuliffe, so I don't see how this is an issue. Especially since it's not like Ds are really relevant at all on the Eastern Shore or in Western Maryland.