A leafleting campaign he undertook for the (illegal) Communist Party led to several months of solitary confinement and a conviction from a federal court.
Antisemitism, till that point little more than an exceptionally rich seam of shrill slogans for populist politicians, suddenly became a core underpinning of government strategy.
Directly after that the authorities determined that the "Jewish houses" in the quarter were to be cleared for re-use ("entmietet"), so the family had to leave their apartment.
[4] Their father had refused to divorce his Jewish wife and for this reason the authorities decided that, as "half-Jews", they fell outside the classification applied to those being deported.
[5] In 1943 Clementine Grube gave permission for her children to be baptised as Christians in order that their racial classification might be reassessed by the authorities.
Grube joined the rush to the large air-raid shelter opposite the secondary school and the main railway station, but someone spotted his "Jew star" and he was prevented from entering.
[5] In postwar Munich Grube gained an acute sense of the way in which old National Socialists were integrated into the power structures of the new democracy, doing what they could to prevent the lessons of fascism from being passed on to new generations.
The Communist Party also failed to recover its pre-1933 status as a significant political force in West Germany where, especially after 1949, it was almost universally identified as a proxy for the imperialist ambitions of the Soviet Union.
In the early 1950s Grube was engaged in street protests against West German re-armament and against new laws, highly contentious in Bavaria at that time, concerning shop opening hours.
[4][b] This time Grube was sentenced to a seven-month jail term for "resisting state authority" ("Widerstands gegen die Staatsgewalt").
[1][2] This time he received a one-year jail term from the Federal Court of Justice,[9] which included nine months in solitary confinement.
When it became known to his employers in the state controlled education sector that Grube was a DKP member he was faced with a "professional ban" - effectively he was to lose his job because of his party membership.
[10] For anyone familiar with the twelve Nazi years Grube's situation immediately called to mind the infamous Law for the Restoration of the Professional Civil Service ("Gesetz zur Wiederherstellung des Berufsbeamtentums"), passed by the government in April 1933, which had removed Jews and Communists from their jobs across a wide range of public sector departments (including education).
It was only when Ernst Grube turned up at the city hall and placed the yellow "Jew star" with which he had been issued in 1941 on the desk of the responsible official that he authorities changed their collective mind.
[10][4][11] At some point around 1990 Ernst Grube began to make testifying to his experiences as a survivor of National Socialist racism the focus of his life's work.