CDU/CSU

Both the CDU and the CSU were established after World War II and share a perspective based on Christian democracy and conservatism and hold the dominant centre-right position in the German political spectrum. The CSU is usually considered the de facto successor of the Weimar Republic–era Bavarian People's Party (BVP), which itself broke away from the all-German Catholic Centre Party (DZP) after World War I, but the CSU included also parts of the agrarian and liberal Bavarian Peasants' League and parts of the bavarian wing of the DVP. However the CDU's foundation was the result of a major re-organisation of the centre-right political camp compared to the Weimar Republic. Although the CDU was largely built as the de facto successor of the Centre Party, it successfully opened out to non-Catholic Christians (many of them affiliated with the German People's Party until 1933) and successfully asserted itself as the only major conservative party (outside of Bavaria) against initial competition from other Catholic, Protestant or national conservative parties such as the German Party during the early years of the Federal Republic.

The BVP became the sister party of the DZP and they did not compete against each other except for the May 1924 German federal election, the 1924 Bavarian state election and the 1925 German presidential election. The DZP and BVP were mostly jointly represented at the Imperial governments. Similarly to the modern CDU/CSU split, the Bavarian People's Party was generally seen as the party further to the political right, as evidenced by the 1925 second round of the presidential election when the Center Party backed Rhenish Catholic and Weimar Coalition candidate Wilhelm Marx while the BVP made common cause with the monarchist and nationalist parties in backing Prussian junker and former general Paul von Hindenburg despite him being a Protestant and the long-standing mutual animosity between Bavaria and Prussia.

For short periodes of time, there existed

• the Christian People's Party of the Saarland as sister party of the CSU during the 1957 West German federal election,
• the German Social Union (DSU) as sister party of the CSU before the 1990 East German general election,
• the East German CDU as sister party of the CDU until the German reunification and
• the Baden Christian-Social People's Party until 1947.

Alliance for Germany was a coalition for the 1990 East German general election consisting of the CDU, the DSU and Democratic Awakening which merged into the CDU.

CSU party rally in June 1976. On the right Franz Josef Strauß, the CSU leader since 1961, on the left Helmut Kohl, leader of the federal CDU since 1973 and main candidate for the general elections in October 1976.

During the 1970s and then again after 2015, several CSU leaders have expressed the wish to make the CSU a truly independent party without formal ties to the CDU. Usually they combined this wish with an expansion to the rest of Germany.

After 1969, CDU and CSU were in the opposition in the Bundestag. CDU leader Kohl wanted to win the liberal FDP again for a coalition with the CDU/CSU, while the CSU leader Strauß had different plans. He aimed for a right wing majority without the FDP. Additionally, Strauß thought little of the current CDU leader Kohl, a more moderate Christian Democrat.

Strauß believed that CDU and CSU should be separate national parties to address different audience: the CDU the moderate, social and liberal voters, the CSU the conservative voters. After the elections they should still form a government together.

In 1975, the federal CDU declared Kohl to be the next CDU/CSU chancellor candidate for the 1976 general elections - without consulting the CSU.[7] Kohl did well in the elections on October 3, 1976, although Social Democrats and FDP had still enough seats to continue their coalition. Kohl decided to leave his post as prime minister of the state of Rhineland-Palatinate for the chairmanship of the CDU/CSU Bundestag faction.

The Hans-Seidel-Stiftung is a political foundation linked to the CSU. From 1975 to 2016, it had an educational centre in this building in the municipality of Kreuth, close to the Austrian border. For decades, spirit of Kreuth was a reference to an independent, conservative CSU.

In November that year, the 49 CSU Bundestag members gathered in the party's educational centre in Wildbad Kreuth, Southern Bavaria. 30 of them voted for a proposal to form a CSU Bundestag parliamentary group of its own. CDU leader Kohl was informed only later via the media.[8] This 'Kreuth separation decision' (Kreuther Trennungsbeschluss) was a major political earthquake and caused the CDU to react swiftly and resolutely. Kohl threatened the CSU by preparing the creation of a CDU party organization in Bavaria. In March 1977, the CDU Bayern was supposed to be founded in Nuremberg.[9]

During the conflict, the Aktionsgemeinschaft Vierte Partei, the Bund Freies Deutschland (West-Berlin), the Christlich Soziale Wähler Union (Saarland), the Deutsche Union (North Rhine-Westphalia) and the Partei Freier Bürger (Bremen) were founded. On 12 December 1976, the vote was rescinded after the CDU had threatened in turn to form local associations within Bavaria and to run in Bavarian elections against the CSU.

Strauß himself polemicised against Kohl in a closed CSU meeting on November 24 (this Wienerwald speech was leaked, and published on November 29 in Der Spiegel):

That Helmut Kohl will never become chancellor. Being 90 he will write his memoirs: 'I was chancellor candidate for 40 years; lessons and experiences from bitter times.' The last chapter written maybe in Siberia or elsewhere.

— Franz Josef Strauß[10]

It turned out that most local CSU leaders and also conservative CDU state leaders did not approve a separation between CSU and CDU. The CSU Bundestag members revoked their decision. On December 7, the CDU/CSU Bundestag group elected Kohl as its chairman.[11] In 1980, Strauß was the joint CDU/CSU chancellor candidate and lost more than 4 percent of the votes. This ended his ambitions for a federal CSU.

The Munich scandal of November 2015: Horst Seehofer, CSU leader and Bavarian minister-president, with CDU leader and chancellor Angela Merkel, at the 2015 CSU party rally. At this occasion, Seehofer humiliated his guest by letting her stand next to him for minutes while he lamented her liberal politics with regard to refugees.[12]

Under the chairmanship of Angela Merkel (2000-2018), the CDU left some right wing positions behind and shifted more to the political centre. Especially the 2015 refugee crisis divided the German population and caused conflict between the more liberal CDU and the more anti migrant party CSU.

Therefore, a federal CSU was discussed again among party members and journalists. For example conservative Welt columnist Ansgar Graw wrote in 2016 that CDU and CSU lost its stance as a law and order party. As Merkel's CDU could not move to the right without losing credibility, Graw called the CSU to become a federal party, a right wing party that rigorously deports asylum seekers without right to stay.[13] On the contrary, former CSU leader Theo Waigel warned against a separate election campaign. In such a campaign, CDU and CSU would fight much more each other than the rest of the parties.[14]

In 2018, Interior Minister Horst Seehofer, a former Minister-President of Bavaria and the leader of the CSU, opposed CDU Chancellor Angela Merkel's policy on Syrian refugees in Germany. Seehofer hoped to place restrictions on incoming refugees, many of whom enter the country through Bavaria. His stance was seen as being in part motivated by the 2018 Bavarian state election in which it was feared that the far-right Alternative for Germany would make gains. The dispute threatened to bring down the Merkel government which relied on the CSU for its parliamentary majority as Seehofer had indicated his resignation on 2 July, but he already rescinded it a day later after an agreement over the issue between the coalition parties (the CDU, the CSU and the SPD) had been reached.[15]

In June 2018, CDU and CSU Bundestag members held separate meetings on the topic of refugees, which was highly unusual. A fake Twitter account announced that CSU leader Seehofer had abolished the CDU/CSU alliance and that CDU vice chair Bouffier had called for a CDU in Bavaria. Many journalists published the news, which was interpreted by the Merkur as a sign that such events are considered no longer absurd or unlikely.[16] Political scientist Heinrich Oberreuter did not believe in Seehofer's threat to expand the CSU to the rest of Germany. Both parties aim essentially for the same voters. As separate parties in the general elections both would lose voters. The CSU would lose its unique selling point as a Bavarian party. With a CDU in Bavaria, the CSU would fall from 47 to 30 percent in Bavaria.[17]

A federal CSU was again discussed prior to the general elections of 2021. CSU leader Markus Söder was unhappy about the CDU decision to declare CDU leader Armin Laschet the chancellor candidate and successor of Angela Merkel. In September 2020, the CSU created online memberships for people not living in Bavaria. A survey in May 2021 foresaw that a federal CSU may win at least 9 percent of the votes, especially in Eastern Germany and among FDP voters.[18]

Both parties suffered heavy losses in elections after 2017. In the Bavarian state elections of October 2018, the CSU lost 10.5 percent. With 37.2 percent, this was its worst election result since 1950. In the federal elections of 2021, the CDU lost 7.9 percent and the CSU 1.0 percent of the (party list) votes.