2020 US Senate Election- What will be the 51st Democratic US Senate seat?

[nkpolitics1212]

1-35)Democratic held US Senate seats not up for re-election in 2020.
36-46)Democratic held US Senate seats up for re-election in 2020 likely to stay in the Democratic column.
36)RI(Reed-D)
37)MA(Markey/Kennedy-D)
38)NJ(Booker-D)
39)IL(Durbin-D)
40)DE(Coons-D)
41)OR(Merkley-D)
42)VA(Warner-D)
43)NM(Lujan-D)
44)NH(Shaheen-D)
45)MN(Smith-D)
46)MI(Peters-D)
47-51)Republican held US Senate seats up for re-election in 2020 likely to go to the Democratic column.
47)CO(Gardner-R)Hickenlooper-D
48)AZ special(McSally-R)Kelly-D
49)ME(Collins-R)Gideon-D
50)NC(Tillis-R)Cunningham-D
51)KS(OPEN Roberts-R)Bollier-D vs Kobach-R. or MT(Daines-R)Bullock-D