2018 and 2020 US Senate Election -most vulnerable Democratic and Republican held seat.

2018-Most Vulnerable Democratic held seat
IN-Donnelly-D vs Messer-R
MO-McCaskill-D vs Hawley-R
2018-Most Vulnerable Republican held seat
AZ-Ward-R vs Stanton-D (Flake-R loses in primary)
NV-Heller-R vs Rosen-D
2020-Most Vulnerable Democratic held seat
NH-Shaheen-D vs Sununu-R
2020-Most Vulnerable Republican held seat
AZ(Special)-McSally-R vs Sinema-D
CO-Gardner-R vs Hickenlooper-D
ME(OPEN)-Poliquin-R vs Pingree-D
MT-Daines-R vs Bullock-D
NC-Thillis-R vs Stein-D