Trump 60%
Biden 35%
Sure, it’s still a solid Republican county which usually votes well to the right of the state, but there’s zero chance Trump does better here in 2020 than in 2016, even against "someone like Sanders or Warren."
Yes, Blackburn only won by 18 here but that was after the TN Dems nominated their best possible candidate whose top targets included Williamson County.
Williamson County is also part of TN-07, a district she represented in Congress for 16 years, so the fact that she "only" won by 18 is quite significant.
