1)WI(Johnson-R) loses to Barnes-D by a narrow margin.
2)NV(Cortez Masto-D) vs Laxalt-R
3)GA(Warnock-D) vs Walker-R
4)AZ(Kelly-D) vs Brnovich-R
5)FL(Rubio-R) vs Demings-R.

OPEN US Senate seats up for re-election in 2022 that is likely to switch parties.
1)PA(OPEN Toomey-R)Fetterman-D
2)NC(OPEN Burr-R)Beasley-D
3)OH(OPEN Portman-R)Ryan-D

OPEN seat
AL(Brooks-R)
MO(Greitens-R or Schmitt-R)
NC(Beasley-D or Budd-R or McCrory-R)
OH(Ryan-D or Mandel-R or Timken-R or Vance-R)
PA(Fetterman-D)
VT(Welch-D)
Vulnerable incumbent
WI(Barnes-D)
If 2022 is a Republican wave.
AZ(Brnovich-R),GA(Walker-R) and NV(Laxalt-R)

Johnson(R-WI),Cortez Masto(D-NV),Warnock(D-GA), Rubio(R-FL),or Kelly(D-AZ)?
Johnson(R-WI) is most likely to lose re-election. Cortez Masto(D-NV),Kelly(D-AZ), and Warnock(D-GA) survive due to the weakness of the Republican challengers. Rubio(R-FL) seat could go either way.

Regarding the OPEN US Senate seats.

PA(OPEN Toomey-R) is most likely to flip. After that is NC(OPEN Burr-R),and OH(OPEN Portman-R).
VT(OPEN Leahy-D) stays in the Democratic column. AL(OPEN Shelby-R) and MO(OPEN Blunt-R) stays in the Republican column.

37)HI(Schatz-D)
38)NY(Schumer-D)
39)CA(Padilla-D)
40)MD(Van Hollen-D)
41)CT(Blumenthal-D)
42)VT(Welch-D)
43)OR(Wyden-D)
44)IL(Duckworth-D)
45)WA(Murray-D)
46)CO(Bennet-D)
47)NH(Hassan-D)
48)NV(Cortez Masto-D)
49)AZ(Kelly-D)
50)PA(Fetterman-D)
51)GA(Warnock-D)
52)WI(Barnes-D)

PA and WI are the 2 Republican held US Senate seats up for re-election in 2022 that the Democrats will win. NC and OH are Tossups. FL,MO, and IA will remain Republican.

On the Democratic side- The vulnerable seats are NV,AZ, and GA but these seats will remain in the Democratic column.

37)HI(Schatz-D)
38)NY(Schumer-D)
39)CA(Padilla-D)
40)VT(Welch-D)
41)MD(Van Hollen-D)
42)OR(Wyden-D)
43)CT(Blumenthal-D)
44)IL(Duckworth-D)
45)WA(Murray-D)
46)CO(Bennet-D)
47)NH(Hassan-D)
48)NV(Cortez Masto-D)
49)AZ(Kelly-D)
50)GA(Warnock-D)
51)PA(Fetterman-D)
52)WI(Barnes-D)
53)NC(Beasley-D)

Brown won by a 12 percent margin in 2006 against a 2 term Republican incumbent(Mike DeWine who is now Governor.)
Brown won by a 6 percent margin in 2012 and 7 percent margin in 2018.
If Brown decides to run for re-election in 2024 it will be by a 1 to 2 percent margin.

HI(Schatz-D)
NY(Schumer-D)
CA(Padilla-D)
VT(Welch-D)
MD(Van Hollen-D)
OR(Wyden-D)
CT(Blumenthal-D)
IL(Duckworth-D)
WA(Murray-D)
CO(Bennet-D)
NH(Hassan-D)
AZ(Kelly-D)
NV(Cortez Masto-D)
GA(Warnock-D)
PA(Fetterman-D)
WI(Barnes-D)
NC(Beasley-D)

1)PA(OPEN Toomey-R)
2)WI(Johnson-R)
3)NC(OPEN Burr-R)
4)GA(Warnock-D)
5)NV(Cortez Masto-D)
6)AZ(Kelly-D)
7)OH(OPEN Portman-R)
8)NH(Hassan-D)
9)FL(Rubio-R)
10)CO(Bennet-D)

WI(Johnson-R) is the most vulnerable incumbent US Senator seeking re-election in 2022.

The second most vulnerable OPEN US Senate seat up for re-election in 2022 is NC(OPEN Burr-R).

Democrats are more likely to win PA,WI,and NC than Republicans are more likely to win AZ,NV, and GA.

37)HI(Schatz-D)
38)NY(Schumer-D)
39)CA(Padilla-D)
40)MD(Van Hollen-D)
41)CT(Blumenthal-D)
42)VT(Welch-D)
43)OR(Wyden-D)
44)IL(Duckworth-D)
45)WA(Murray-D)
46)CO(Bennet-D)
47)NH(Hassan-D)
48)NV(Cortez Masto-D)
49)AZ(Kelly-D)
50)PA(Fetterman-D)
51)GA(Warnock-D)
52)WI(Barnes-D)
53)NC(Beasley-D)
54)OH(Ryan-D)