Karner was politically active as a local councilor in Texingtal from 1995, and from April 24, 2003 also as an ÖVP member in the Lower Austrian state parliament.

[9] Shortly after he was sworn in as Minister of the Interior, accusations of anti-Semitism were raised against him in a press release from his time as state manager of the ÖVP Lower Austria.

[10][11] In this press release he accused the SPÖ of Lower Austria of working "with gentlemen from America and Israel against the country", with which Karner used anti-Semitic stereotypes for the Jewish Austrian students (JöH).

The signers of this letter include the writer Elfriede Jelinek, the author Doron Rabinovici and the former OGH President Irmgard Griss.

Karner defended himself by saying that taking a stand against anti-Semitism was a "personal concern" to him and that during the election campaign "words and sentences were generally used that one would probably no longer use in the same way afterwards".

Karner himself denies the allegations: According to him, he wrote the entire work “according to good scientific practice and to the best of my knowledge and belief”, and he looks forward to an examination of any kind “with composure”.