In 1,993 responses to a Sex Survey questionnaire, responses consisted of 1,351 males and 642 females.   Progressives were over-represented (N=973), while Conservatives were under-represented (N=395).

Nevertheless, Charles Brack at Neuropolitics.org says he can find some meaning in it; namely that Conservatives have retained a distinctive reproductive valence to their sexual behavior, while progressives have substantially undermined fertility in their sex lives, and seem to be adapting a sort of 'sociosexuality'; that is, sex that has lost its reproductive significance, and now performs social functions, such as neutralizing intra-group competition and aggression.

The Secret Sex Lives of Conservatives and Liberals - Charles Brack, Neuropolitics.org
 

Gender
Political Cohort
N
Children Wanted
Length of Current Relationship (in months)
Heterosexuality
Number of sex partners
Female
NP
52
2.5
44
8.5
15.6
Female
VL
176
1.8
89
7.2
16.0
Female
L
199
2.0
86
7.9
13.8
Female
M
107
2.4
98
8.2
11.6
Female
LB
51
1.8
100
8.1
11.6
Female
C
43
2.4
128
9.1
8.5
Female
VC
14
2.5
131
9.4
3.9
Male
NP
87
1.7
100
9.1
15.8
Male
VL
285
1.6
89
8.0
16.9
Male
L
313
1.9
97
8.3
16.1
Male
M
171
2.2
128
8.9
16.0
Male
LB
157
2.1
104
8.6
15.2
Male
C
222
2.7
146
9.2
15.7
Male
VC
116
3.2
150
9.5
12.9

Children wanted, length of relationship, heterosexuality, and number of sex partners, by gender and political affiliation
(NP=Nonpolitical, VL=Very Liberal, L=Liberal, M=Moderate, LB=Libertarian, C=Conservative, VC=Very Conservative)