AZ(Stanton-D vs the appointed Republican incumbent-R)
CO(Crow-D or Neguse-D vs Gardner-R)
IA(Finkenauer-D vs Ernst-R)

Districts that have an EVEN to +D PVI.
1)CA-10(Denham-R)
2)CA-25(Knight-R)
3)CA-39(OPEN Royce-R)
4)CO-6(Coffman-R)
5)FL-26(Curbelo-R)
6)FL-27(OPEN Ros Lehtinen-R)
7)IA-1(Blum-R)
8)MN-3(Paulsen-R)
9)PA-5(VACANT-Meehan-R)
10)PA-6(OPEN Costello-R)
11)PA-7(VACANT-Dent-R)
12)VA-10(Comstock-R)
13)WA-8(OPEN-Reichert-R)
Districts that have a +1R PVI
14)AZ-2(OPEN- McSally-R)
15)CA-49(OPEN-Issa-R)
16)NJ-2(OPEN- LoBiondo-R)
17)PA-1(Fitzpatrick-R)
18)TX-23(Hurd-R)
Districts that have a +2R PVI
19)MN-2(Lewis-R)
20)NY-19(Faso-R)
Districts that have a +3R PVI
21)NJ-7(Lance-R)
22)NJ-11(OPEN-Frelinghuysen-R)
23)PA-17(Rothfus-R vs Lamb-D)
Districts that have a +4R PVI
24)CA-48(Rohrabacher-R)
25)MI-11(OPEN-Trott-R)
26)NE-2(Bacon-R)

In the 2006 US Senate Election cycle Democrats needed a net gain of 6 seats to get in the majority. They held onto every Democratic held seat up in 2006 and picked up PA,OH,RI,MO,MT,and VA. The VA US Senate seat was won due to incumbent Republican George Allen making the Macaca gaffe.
In the 2018 US Senate Election cycle Democrats need a net gain of 2 seats to get in the majority. Democrats have an easy chance of picking up 3 Republican held US Senate seats in 2018. AZ,NV,and TN(Bredesen-D 2018 performance will better than Ford-D 2006 performance). On the other hand Democratic incumbents in strong Trump states IN(Donnelly-D) and ND(Heitkamp-D) could narrowly lose barring a gaffe by the Republican challenger. Democrats have a net gain of 1 seat. Democrats will need to win TX(Cruz-R could the George Allen of 2018).

2018 US House.
Democrats will win Republican held US House seats in
1)AZ-2
2)CA-10
3)CA-25
4)CA-39
5)CA-48
6)CA-49
7)CO-6
8)FL-26
9)FL-27
10)IL-12
11)IA-1
12)MI-11
13)MN-2
14)MN-3
15)NE-2
16)NJ-2
17)NJ-7
18)NJ-11
19)NY-19
20)NY-22
21)NC-9
22)OH-12
23)PA-1
24)PA-5
25)PA-6
26)PA-7
27)PA-17
28)TX-23
29)VA-10
30)WA-8
31)WI-1
Democrats will lose PA-14
2018 US Senate
Democrats will pick up AZ and NV, but will lose in IN. +1D 50D 50R (VP Pence-R breaks the tie)
2020 US Senate
Democrats will pick up AZ special,CO,and NC, but will lose in AL. +2D. 52D 48R

PA-4(Madeleine Dean-D)
PA-5(Marcia Gay Scanlon-D)
PA-6(Chrissy Houlihan-D)
PA-7(Susan Wild-D)
PA-14(Bibiana Boerio-D)

The most vulnerable Democratic US Senators up for re-election in 2018 are limited to the Trump States.
MI(Stabenow-D),PA(Casey-D),and WI(Baldwin-D) are favored to win by a double digit margin.
MT(Tester-D),OH(Brown-D),and WV(Manchin-D) are favored to win by a high single digit margin.
FL(Nelson-D),IN(Donnelly-D),MO(McCaskill-D)and ND(Heitkamp-D) are favored to win by a narrow margin.

Democrats are going to pick up Republican held US Senate seats in AZ- both seats assuming McCain leaves before May 31, 2018, NV, and TN. +3D to +4D

If McCain leaves before May 31, 2018, the AZ US Senate seat should remain VACANT until the November 2018 election.
If McCain leaves after May 31,2018, the AZ US Senate seat should remain VACANT until the next Governor of AZ is sworn in. If the Democratic Nominee wins the 2018 AZ Governors Race, that person gets to fill the vacancy until the 2020 Special Election.

2018 US Senate.
Republican held US Senate seats likely to go Democratic
AZ(OPEN Flake-R) Sinema-D
AZ(VACANT McCain-R) Kelly-D,Gallego-D,Stanton-D,or Kirkpatrick-D
NV(Heller-R)Rosen-D
TN(OPEN Corker-R) Bredesen-D
+2D to +4D
Democratic held US Senate seats that could go Republican
IN(Donnelly-D)Braun-R
+1D to +3D
2018 US House
Republican held US House Seats likely to go Democratic
AZ-2
CA-10
CA-25
CA-39
CA-48
CA-49
CO-6
FL-26
FL-27
IL-12
IA-1
MI-11
MN-2
MN-3
NE-2
NJ-2
NJ-7
NJ-11
NY-19
NY-22
PA-1
PA-5
PA-6
PA-7
PA-17
TX-23
VA-10
WA-8
+28D
Democratic held US House Seats likely to go Republican
PA-14
MN-1
MN-8
+25D
Democrats could pick up IL-6,KS-2,NC-9,TX-7,and WI-1

2018
AZ(OPEN Flake-R)Sinema-D
NV(Heller-R)Rosen-D
TN(OPEN-Corker-R)Bredesen-D
2020
AZ(VACANT McCain-R)Kelly-D
CO(Gardner-R)-Perlmutter-D
ME(OPEN Collins-R)-Pingree-D
MT(Daines-R)Bullock-D
NC(Tillis-R)Cowell-D
2022
FL(Rubio-R)Murphy-D
NC(OPEN Burr-R)McCready-D
PA(Toomey-R)Lamb-D
WI(OPEN Johnson-R) Kind-D

1)AZ-2
2)CA-10
3)CA-25
4)CA-39
5)CA-48
6)CA-49
7)CO-6
8)FL-26
9)FL-27
10)IL-6
11)IL-12
12)IA-1
13)KS-2
14)MI-11
15)MN-2
16)MN-3
17)NE-2
18)NJ-2
19)NJ-7
20)NJ-11
21)NY-19
22)NY-22
23)NC-9
24)PA-1
25)PA-5
26)PA-6
27)PA-7
28)PA-17
29)TX-7
30)TX-23
31)VA-10
32)WA-8
33)WI-1