On 31 August 1925 Karpenstein joined the re-founded Nazi Party (membership number 17,333). As an early Party member, he later would be awarded the
Golden Party Badge. He served as the Party
Ortsgruppenleiter (Local Group Leader) for
Darmstadt for the next four years. In 1929, after passing the bar exam, Karpenstein returned to
Greifswald where he worked as a lawyer. He was also appointed Nazi
Kreisleiter (County Leader) for Greifswald. On 9 September 1930, he was elected to the
Reichstag for electoral constituency 6,
Pomerania. The following year, he became the editor of the
Pommerschen Zeitung, a National Socialist newspaper. On 1 April 1931, Karpenstein was appointed
Gauleiter of Pomerania to succeed
Walther von Corswant. After the Nazis came to power a significant amount of autonomy lay with the
Gauleiters, and their radicalism threatened to disrupt the relationship between
Adolf Hitler and the middle classes that had helped to ensure Nazi electoral strength. Karpenstein did not present this problem, as he was conservative and pro-middle class. Despite not holding
left-wing economic ideas himself, Karpenstein was too weak to control the dissident sentiments emerging from the
Sturmabteilung (SA) in Pomerania, which was one of their power bases. However, he sought every opportunity to increase his personal power by seeking to make all of the churches, government officials and media outlets in Pomerania answerable to him directly. In addition to his party post, Karpenstein also occupied many governmental positions. In March 1933, he was named a member of the Pomeranian Provincial
Landtag, and he also served on the Pomeranian Provincial Council. He also was one of the Prussian representatives to the
Reichsrat until its
abolition on 14 February 1934. In September 1933 he became a member of the
Prussian State Council . However, unlike many other
Gauleiters, Karpenstein did not succeed in obtaining the office of Provincial
Oberpräsident, after the removal of
Carl von Halfern on 1 October 1933. Karpenstein's career ended abruptly in July 1934. Charges of involvement in the
Röhm Putsch, of homosexuality and of repeated noncompliance with orders issued by the Party leadership were brought against him. Following a hearing by
the Supreme Party Court, Karpenstein was deposed as
Gauleiter of Pomerania in favor of
Franz Schwede-Coburg on 21 July 1934 and expelled from the party. His lack of direct involvement with the SA probably saved him from being killed. Ostensibly, however, Karpenstein was dismissed for his supposed links to
Gregor Strasser and his failure to work with
Hermann Göring. == Later years ==