Chittenden County, Franklin County, Grand Isle County. These three northwestern counties of Vermont had kind of become Democratic enclaves in an otherwise Republican state. Republicans carried them in landslides, but their margins were much smaller compared to the other counties.
AFAIK - not even whole
Chittenden county. There were (and even - there are) some very successful Republican politicians from Chittenden county. And there is a sort of irony that Franklin county is among less Democratic counties now.