Braun's tenure in politics has been marked by controversy, including inflammatory remarks during the COVID-19 pandemic and endorsements of independent nuclear capabilities for Poland.

He is involved with "Wake-up Call" ("Pobudka"), an organisation that he has founded[11] to strengthen the self-sustainability of faith communities and the internet show Sumienie Narodu.

[5] New Conservatives Defunct Historical In September 2012, Braun called for the execution by firing squad of journalists from Gazeta Wyborcza and TVN,[14] which led to an official investigation.

[20] In the 2019 European Parliament election in Poland Braun was the leading candidate for the Confederation Liberty and Independence in the 9th constituency encompassing the territory of the Subcarpathian Voivodeship (Podkarpackie in Polish).

Although his list received 5.89% of the vote, the best result for Confederation in the country, the coalition failed to reach the 5 per cent threshold nationwide and so he did not pick up the seat.

[21] In the 2019 Polish parliamentary election Braun was the leading candidate for the Confederation Liberty and Independence in the Rzeszów Constituency, located in the Podkarpackie Voivodeship.

[25] Niedzielski, along with the Speaker of the Sejm, Elżbieta Witek, filed to press punishable threat charges against Braun, which were later dropped by the prosecutor citing "no signs of a crime".

However, the court sustained the prosecutor's decision and provided an explanation that Braun's words, while inappropriate, were merely criticism, and that Niedzielski's alleged fear would have been irrational.

[30] During a debate in the European Parliament, Braun stated, that the military aid to Ukraine is not helping the Ukrainian people, but only prolonging the war, after which his microphone was cut off.

[31] On 27 January 2023, Braun destroyed a Christmas tree decorated with baubles themed with Ukrainian, EU and LGBT pride flags located in the building of the Kraków District Court.

[38] On 12 October, Braun stated, that "the Polish Army should not lift a finger in the defense of a small, depopulated, nasty, anti-Polish, Bismarck, Anglo-Saxon and Jewish creature, that is modern Lithuania".

[40] He declared his intent despite the fact that the Confederation Liberty and Independence (KWiN) leadership had designated Mentzen as party's presidential candidate back in August 2024.

[44] On 30 May 2023, Braun disrupted a lecture on the Holocaust by the historian Jan Grabowski at the German Historical Institute in Warsaw by invading the room and destroying the event's microphone and speakers.

[27] On 12 December 2023, during the first session of the 10th term of Sejm, he put out a Hanukkah menorah by spraying it with a fire extinguisher, saying that "The people participating in the Satanic cult should be ashamed".

Prosecutors previously said that they intended to charge him with seven counts also included earlier incidents of alleged aggression against a former health minister and public property.

[54] On 29 January 2025, Braun disrupted a moment of silence held during European Parliament's sitting in commemoration of the International Holocaust Remembrance Day by shouting "Let's pray for the victims of the Jewish genocide in Gaza".