Cross-posted at iHartPolitics.com.

Rasmussen Reports is out with a new national GOP primary poll. A previous poll was conducted in August just days after Rick Perry announced his candidacy.

Looking at the detailed demographics here’s what Ras. says:

20-Sep
15-Aug
+/-

Perry
28%
29%
-1%

Romney
24%
18%
6%

Bachmann
8%
13%
-5%

Cain
7%
6%
1%

Paul
6%
9%
-3%

Santorum
3%
1%
2%

Gingrich
9%
5%
4%

Huntsman
2%
1%
1%

McCotter
1%
0%
1%

Not sure
11%
16%
-5%

 

The big headline: Bachmann is imploding. Her support across all demographics has basically halved. Interestingly enough, much of that support seems to be moving to Romney. (Gingrich’s performance during the debates has also brought in notable support.)

Let’s look deeper at the Male/Female breakdown

Male – 9/20
Male – 8/15
+/-
Female – 9/20
Female – 8/15
+/-

Perry
28%
32%
-4%
28%
25%
3%

Romney
22%
20%
2%
26%
17%
9%

Bachmann
9%
12%
-3%
7%
14%
-7%

Cain
9%
6%
3%
6%
6%
0%

Paul
9%
11%
-2%
4%
7%
-3%

Santorum
3%
2%
1%
3%
1%
2%

Gingrich
9%
6%
3%
9%
4%
5%

Huntsman
2%
2%
0%
3%
1%
2%

McCotter
0%
0%
0%
1%
0%
1%

Not sure
9%
9%
0%
12%
24%
-12%

 

Bachmann’s support among women dropped dramatically. Undecided women are also moving quickly to make a decision. Both Romney and Perry increased their female prowess while Perry shed the most male votes over the past month.

Next, let’s look at age. The story here: Ron Paul’s youth vote is disintegrating according to Rasmussen. (Grain of salt: b/c these polls usually don’t reach younger voters in high frequencies these numbers can vacillate greatly)

(18-29) 9-20
(18-29) 8-15
+/-

Perry
19%
17%
2%

Romney
13%
8%
5%

Bachmann
9%
5%
4%

Cain
13%
5%
8%

Paul
10%
29%
-19%

Santorum
8%
0%
8%

Gingrich
12%
7%
5%

Huntsman
6%
2%
4%

McCotter
6%
0%
6%

Not sure
5%
27%
-22%

 

Bachmann gain votes among 30-somethings but the 40+ crowd was not kind to her.

But now, the big question… did Social Security hurt Perry? Here’s the 65+ demo:

65+ 9/20
65+ 8/15
+/-

Perry
31%
34%
-3%

Romney
33%
22%
11%

Bachmann
6%
15%
-9%

Cain
3%
3%
0%

Paul
5%
2%
3%

Santorum
2%
1%
1%

Gingrich
6%
6%
0%

Huntsman
1%
1%
0%

McCotter
0%
0%
0%

Not sure
14%
16%
-2%

 

-3% points is well within the margin of error but it was the biggest demo loss for Perry and Romney’s biggest demo gain. If you add the 50-64 demo to the 65+ crowd Romney saw an increase of 12% and Perry dropped 4%.

Given the ratio of likely voters for older demographics it’s not without the realm of possibility that the vast majority of Romney’s gains and Perry’s losses came in the older demographics.

But I’m more inclined to say that Bachman’s implosion and decreased fence-sitters are the big story here.

Stay tuned.