North Rhine Westphalia

[palandio]

Good that you mentioned the Saarland. The Saarland actually has the highest percentage of Catholics among all German Länder (even higher than Bavaria). Until the 70s a majority voted for Christian Democratic parties, but in the 2013 federal election even with the Left on the ballot the SPD polled 31.0% in Saarland (vs. 25.7% nationally) and the CDU only 37.8% (vs. 41.5% nationally).

Confession is a very important factor in German voting traditions that you can often spot easily on the maps, but it is by far not the only factor and there are many CDU Protestants and SPD Catholics depending on region, socio-economic factors etc.
If you look at election maps it is plausible that SPD support among Rhenish Catholics is substantially higher than among Sothern Catholics, probably even higher than among Eastern unaffiliateds.

[palandio]

Oberbergischer Kreis
39.9% Evangelical Church in Germany
31.4% Roman Catholic Church
  5.2% Evangelical Free Churches
  4.9% Other official religion
18.6% No official religion (includes all Muslims except Ahmadiyya)

Rheinisch-Bergischer Kreis
28.7% Evangelical Church in Germany
41.2% Roman Catholic Church
  1.3% Evangelical Free Churches
  4.5% Other official religion
24.3% No official religion

Total North-Rhine Westfalia
28.5% Evangelical Church in Germany
42.5% Roman Catholic Church
  1.1% Evangelical Free Churches
  5,4% Other official religion
22.5% No official religion

So yes, Oberbergischer Kreis is plurality evangelical, but evangelicalism is not really dominant. Free church evangelicals which are relatively numerous in the Oberbergischer Kreis are usually more conservative-leaning than EKD evangelicals. And in the 2012 Landtag elections the SPD won one of its two constituencies and got a plurality of Zweitstimmen in both. Altogether even the exception can partially be explained.

[palandio]

Franconia, like the rest of Bavaria, has certainly drifted to the right because of its relatively popular conservative government.

It should also be noted that while the Nuremberg metro and the areas around Hof and Coburg have quite a strong left-wing tradition, in other parts of Franconia the SPD (and KPD) was negligible before 1945. That holds particularly true for the rural western part of Middle Franconia, which was a stronghold of the German National People's Party and then of the NSDAP.

I fear that Ethelbert is not right about the FDP voting protestants in Bavaria. The FDP in Bavaria has almost no political tradition except for maybe a handful dentists from Lake Starnberg. (Edit: You are right that the FDP was more popular among protestant than among catholics, but nowhere in Baden-Wuerttembergish dimensions.)

Palatine on the other hand is quite amazing. Look at Kusel.

[palandio]

Baden and Wuerttemberg have been (radical) liberal strongholds at least since the 1848/49 revolution.
During the Weimar Republic the combined left-wing results (SPD+USPD+KPD) were usually 10% or more below the national average, though there was not the same downward trend as in Bavaria.
After 1945 most centrist and right-wing voters went to the CDU, some to the SPD. That's true for almost all of Western Germany, but in Ba-Wue the starting point for the SPD was lower to begin with.

[palandio]

You might find these tables about Weimar federal election results interesting:
http://www.wahlen-in-deutschland.de/wrtw.htm
http://www.wahlen-in-deutschland.de/wrtwbaden.htm
http://www.wahlen-in-deutschland.de/wrtwwuerttemberg.htm
http://www.wahlen-in-deutschland.de/wrtwfranken.htm

(gonschior.de's databank contains tables down to the district level, but seems to be down at the moment.)

Actually Wuerttemberg, Baden and Franconia had quite some heavy industry locally (Daimler, MAN etc.), but I'm not so informed about its proportions.

About the CSU there is a famous quote from the most famous CSU politician of all times, Franz Josef Strauß: "To my right is only the wall". A school comrade of mine, at that time a strong CSU supporter once said: "Black from the outside and brown inside, that's a CSU sausage."

[palandio]

No, it's not the other way round:
Baden was 58.4% Catholics, 39.4% Protestants.
Württemberg was 68.0% Protestants, 30.9% Catholics.
The federal election division of Württemberg included also Hohenzollern (94.3% Catholics, but very small), so that altogether the electoral division of Württemberg (incl. Hohenzollern) had ca. 66% Protestants.

On the farmers' party in Württemberg: The Württembergischer Bauern- und Weingärtnerbund (Wuerttembergish Peasants' and Winegrowers' Association) was very close to the conservative DNVP without being formally part of it.
The Wuerttembergish branch of the DNVP was called Württembergische Bürgerpartei. The word Bürger can mean both citizen and bourgeois. The Bürgerpartei had its focus more on the non-agricultural conservative electorate. In parliaments they usually caucused with the Peasants' Party and the Peasants' Party deputies on the federal level are normally counted as DNVP deputies because they were in the DNVP caucus.

A similar Peasants' Party that basically was a DNVP outfit existed in Thuringia. On the other hand for example the BBB in Bavaria had a very different ideology including peasant radicalism, anti-clericalism etc.

I can only guess about the reasons why Württemberg was relatively resistant to the NSDAP. Keep in mind that the Nazis were relatively hostile to active Christianity, at least before 1933. So right-wing active Protestants rather supported the DNVP, the Peasants' Party or the CSVD.

[palandio]

BBB and post-war BP are not as far away from each other as one might think.

The BBB participated in several Bavarian center-right governments with the Catholic Bavarian People's Party and the Bavarian branch of the DNVP. It was ideologically very heterodox with right-wing, moderate and left-wing politicians in it. Its main issue was the representation of rural and (small) agrarian interests, but differently from most other agrarian parties it was pro-Weimar, pro-democracy. And of course as a party that existed only in Bavaria, they had a particularistic touch (involuntarily). They failed to expand federally.

The BP was more reactionary and was separatistic, which the BBB had not been. But it was not ultra-Catholic. In fact the clerics supported the CSU and at the beginning of the 1950s most "moderate" BP politicians began to flock to the CSU. When the "moderates" had gone, many of the remaining radicals had the same anti-clerical tilt as the BBB. In 1954 the BP participated in a left-center-right four-party government under SPD governor Hoegner.

Altogether I would say that the BP for a short time partially filled the gap left by the BBB. The focus was on separatism and not so much on peasants' interests and yes, the BP was more reactionary while the BBB was strikingly progressive for a Weimar time peasants' party. But there was quite some overlap. The main reason why the BBB did not leave a remaining post-1945 legacy is in my opinion that in the post-war society based on industry and consumption there was no place for small interest-based parties. Note how the CDU/CSU became a super-confessional party, how the SPD after some time attracted voters beyond the classical blue-collar milieu and how at some point they had a combined vote share of over 90%.

An interesting phenomenon in present-day Lower Bavaria is low turnout (much lower than in any other Western German rural area). And there is relatively high support for the Free Voters, the Ecological Democratic Party and in the recent past the Republicans. Maybe that's some kind of BBB heritage.