They’re all the even numbered districts elected in 2008.
Odd numbered districts were elected in 2010.
Republicans:
2 Cowles
8 Darling
10 Harsdorf
14 Olsen
18 Hopper
20 Grothman
28 Lazich
32 Kapanke
Democrats:
4 Taylor
6 Coggs
12 Holperin
16 Miller
22 Wirch
24 Lassa
26 Rissa
30 Hansen