The Catholic south supported Paul Von Hindenburg. In the 1932-election, the Nazi party and the Bayerische Volkspartei ran neck to neck.

Who voted for the Nazis in Germany? Were they protestants, or were they Roman Catholic?
The Bayerische Volkspartei (BVP) ran the government in Bavaria (Bayern), with Munich as the state capital. In the Bavarian Landtag, the BVP got around 32 per cent of the votes in the pre war elections. The BVP secured the Catholic south from the Kulturkampf of Otto Von Bishmark, who tried to limit the Roman Catholic Church power in Germany.
The SPD got 24,2 percent in Bavaria in the 1928, under performing the national result on 29 percent. The Nazi party got 61, per cent of the votes in 1928, outperforming the national average of less than 3 per cent.
In the 1932 election the SPD vote had fallen to 15,5 per cent. The Nazi party got 32,5 per cent, just 0,1 per cent behind the ruling Bayerische Volkspartei.
From these election result, we can see that the Nazi-party did take a lot of SPD voter in the Catholic south as well. But it picked up voters from all parties. Only the ruling BVP held on to its voters bank.
The BVP was the souther arm of the Centrum party, formed to protect Catholicism in Germany. The mother party and its southern arm were dissolved in July 5th 1933. The concordat between Nazi-Germnay and the Pope was signed on July 20th 1933, bringing an end to political Catholicism in Germany.
My comment:
It was easier for Adolf Hitler to silence the Roman Catholics, because they worked for political power and would follow the instruction of the Pope. Political Catholicism and the Nazi-movement merged in 1933.
The Lutheran movement did not have powerful political parties. The Protestant Church split into two.
The German Christians (Deutsche Christen) constituted the strongest Protestant movement in Germany after the 1932 Church elections, with the aim of synthesising Christianity with the ideology of National Socialism. There were various groups within the German Evangelical Church including the Deutsche Christen and opposition factions that later split under the name Confessing Church.
The Nazi Church in Germany became a mix of Roman Catholics and Protestants, who could not see that two antichrists had taken them for a ride. Adolf Hitler and Pope Pius XII.
Written by Ivar