I decided to dig a bit deeper into the support level of the various "caucuses" within the US Congress. I found this website: http://clerk.house.gov/evs/2013/index.asp detailing rollcoll votes.
I noted a few things.
First, between 15 and 36 Democrats would frequently vote with the Republicans on all sorts of issues.
Second, between 35 and 22 Republicans would frequently vote against both other Republicans and all Democrats.
Since all the names are provided it was easy to determine what this was. The first is the "Blue Dog" caucus, and the second, the more hardcore members of the Tea Party.
Examples: http://clerk.house.gov/evs/2013/roll439.xml VS http://en.wikipedia.org/wiki/Blue_Dog_Coalition#Membership
And http://clerk.house.gov/evs/2013/roll503.xml VS http://en.wikipedia.org/wiki/Tea_Party_Caucus
I found an oddity that I did not understand at first. Members voting against approving the minutes from the previous day.
This is just one example of such a vote: http://clerk.house.gov/evs/2013/roll459.xml
The majority of "no" voters are not only Tea Party members, but, Progressive Caucus members as well.
Ironically, this gives us a simple way to measure the support of these various caucuses. Combining this with what we know, I've built this rainbow of approximate support levels for the various wings of the various parties.
47 - "Plain Tea"
43 - "Sweet Tea"
55 - "Tea on the side"
87 - "Ole School GOP"
35 - "Blue Dog"
75 - "Regular Democrat"
60 - "Progressive"
30 - "99%"
The above are estimates. Frequently 2 Republicans or so will vote with the Democrats, but, these will not always be the same 2 persons. That is why this is not as simple as listing everyone or making a pretty map.
The Senate is much more difficult to determine. My estimates (and these are general estimates) are as follows:
9 - "Plain Tea"
9 - "Sweet Tea"
6 - "Tea on the side"
18 - "Ole School GOP"
4 - "Rockefeller Republican"
34 - "Regular Democrat"
15 - "Progressive"
4 - "99%"