In the comments below a weird fact came to light: it does not seem that liberal/Democrat reduced skepticism toward astrology vs. conservatives/Republicans can be explained just by a secularization, and therefore diminished Christian orthodoxy. There are two reasons for this. First, on a priori grounds most people are religious, liberals and conservatives. The difference between the religious and irreligious on this issue would have to be rather large, and the different apportionment across ideology to be striking, for it to drive the division which seems so robust. Second, within the results it seems rather clear that the gap between liberals and conservatives is most evident amongst the religious of both! In other words, secular liberals and conservatives tend to agree (and be skeptical) in relation to astrology. While religious conservatives are skeptical of astrology, as one would expect from orthodox conservative Christians, religious liberals are not. The table below shows some results.

Astrology is….

Very scientific
Sort of scientific
Not at all scientific

Protestant
Liberal
5
31
64

Conservative
5
18
77

Catholic
Liberal
3
35
62

Conservative
6
25
69

No religion
Liberal
6
22
72

Conservative
9
31
60

Atheist & agnostic
Liberal
7
19
74

Conservative
3
22
75

Believe in higher power
Liberal
3
26
71

Conservative
3
31
66

Believe in god sometimes
Liberal
1
28
71

Conservative
19
18
63

Believe in god with doubts
Liberal
3
29
68

Conservative
3
20
77

Know god exists
Liberal
6
35
59

Conservative
6
21
73

Southern Baptist
Liberal
11
33
56

Conservative
7
16
77

United Methodist
Liberal
4
13
83

Conservative
4
23
73

Episcopal
Liberal
4
23
72

Conservative
5
16
80

Bible is Word of God
Liberal
8
41
51

Conservative
6
22
72

Bible is Inspired Word of God
Liberal
5
28
67

Conservative
5
21
74

Bible is Book of Fables
Liberal
3
23
73

Conservative
8
21
71

Humans developed from animals
Liberal
4
25
71

Conservative
8
25
67

Humans did not develop from animals
Liberal
7
37
56

Conservative
5
16
79

Observe the huge ...