In 1935 she was hired by the controversial German actor and Director of the Prussian State Theatre under the Third Reich, Gustaf Gründgens.

Hoppe made no secret of her contacts with the Nazi elite in the 1930s/40s, including being invited to dinner by Hitler.

Four years later after her divorce from Gründgens, Hoppe had a great success as Blanche Dubois in Tennessee Williams's A Streetcar Named Desire, and increasingly played avant-garde roles, written by authors such as Heiner Müller (Quartett, 1994) and Thomas Bernhard, who became her partner in private life as well.

She became a favourite of the young and iconoclastic directors Claus Peymann, Robert Wilson and Frank Castorf.

"German theater has lost its queen", said Claus Peymann of the Berliner Ensemble, whose theatre featured Hoppe's last performance, in Bertolt Brecht's Resistible Rise of Arturo Ui, in December 1997.