Democratic US Senators who will leave the US Senate to get a job in the Federal Executive Branch.

Sanders(I/D- VT)- President.
Governor Scott(R-VT) picks Sanders immediate successor.
High profile VT Republican
Jim Douglas- former Governor(2003-2011)
Brian Dubie- former Lt Governor(2003-2011)
Douglas or Dubie will have to run in the 2021 special election. The winner of the 2021 special election will be a Democrat.
Peter Welch- At Large US House Member.
Peter Shumlin- former Governor(2011-2017)
Klobuchar(D-MN)- Vice President.
Governor Walz(D-MN) picks Klobuchar's immediate successor.
Betty McCollum- MN-4cd US House Member.
Ilhan Omar- MN-5cd US House Member.
Angie Craig- MN-3cd US House Member.
Warren(D-MA) Cabinet Secretary- Treasury or Commerce or HUD.
Governor Baker(R-MA) picks Warren's immediate successor.
High Profile Republican
Karyn Polito- current Lt Governor
Kerry Healey- former Lt Governor.
Polito or Healey will have to run in the 2021 Special Election. The winner of the 2021 special election will be a Democrat.
Katherine Clark- MA-5cd US House Member.
Lori Trahan- MA-3cd US House Member.
Ayanna Pressley- MA 7cd US House Member.

Due to the loss of Democratic held US Senate seats in-
AL(Jones-D) loses in the November General Election
MA(Warren-D) gets appointed to a US Cabinet Secretary Position or POTUS. Gets replaced by whoever Governor Baker-R appoints.
VT(Sanders-I/D) gets elected POTUS. Gets replaced by whoever Governor Scott-R appoints.

Democrats need to win 6 Republican held US Senate seats up for re-election in 2020.
CO(Gardner-R/Hickenlooper-D)
AZ special(McSally-R/Kelly-D)
NC(Tillis-R/Cunningham-D)
ME(Collins-R/Gideon-D)
GA special(Loeffler-R/Warnock-D)
GA regular(Perdue-R/Tomlinson-D)