Grosz considered himself a propagandist of the social revolution. He not only depicted victims of the catastrophe of the First World War - the disabled, crippled, and mutilated - he also portrayed the collapse of capitalist society and its values. His wartime line drawings show him to be a master of caricature. In a 1925 portfolio of prints Grosz ridiculed Hitler by dressing him in a bearskin, a swastika tattooed on his left arm. Until 1927 he also painted large allegorical paintings that focused on the plight of Germany; Count Harry Kessler, a leading intellectual and collector, called these 'modern history pictures.

Grosz was called by some the 'bright-red art executioner,' and indeed his political radicalism was well known. He had joined the German Communist party in 1922. Although a trip to Russia later that year disillusioned him, he continued to work with [radical publisher] Malik Verlag. Feeling out of step with Russia's politics, Grosz resigned from the party in 1923, but the next year he became a leader of Berlin's Rote Gruppe (Red group), an organization of revolutionary Communist artists that prefigured the Assoziation revolutionarer bildender Kunstler Deutschlands (ASSO, Association of revolutionary visual artists of Germany).

By 1929 the political climate in Germany had shifted to the right, and, at best, Grosz's work was considered anachronistic. The periodical Kunst und Kunstler (Art and artists) commented...: 'Dix's Barrikade (Barricade) and Grosz's Wintermarchen (Winter tale) are now curiosities that only have a place in a wax museum, commemorating the revolutionary time. One doesn't make art with conviction alone.' In a somewhat more positive light, Grosz was described as a historical figure in the periodical Eulenspiegel in 1931: 'No other German artist so consciously used art as a weapon in the fight of the German workers during 1919 to 1923 as did George Grosz. He is one of the first artists in Germany who consciously placed art in the service of society. His drawings...are worthwhile not only in the present but also are documents of proletarian revolutionary art.' These comments were more indicative of the magazine's editorial stance than the tenor of the times, however. More in keeping with popular sentiment, Deutsche Kunst und Dekoration (German art and decoration) described Grosz as one-sided and pathological, 'too obstinate, too fanatical, too hostile to be a descendant of Daumier .' Although according to the magazine's art writer he was a master of form, his social point of view was wrongly chosen.

Grosz's reputation as a political activist and deflator of German greatness was no secret. Menacing portents and premonitions of disaster began to haunt him. A studio assistant appeared in a brown shirt one day and warned him to be careful; a threatening note calling him a Jew was found beside his easel. A nightmare he recounted in his autobiography ended with a friend shouting at him 'Why don't you go to America?' When in the spring of 1932 a cable arrived from the Art Students League in New York, inviting him to teach there during the summer, he accepted immediately. After a short return to Germany, where he was advised that his apartment and studio had been searched by the Gestapo, who were looking for him, the artist emigrated in January 1933. He became an American citizen in 1938.

In the meantime Grosz was among the defamed artists whose works had been included in two Schandausstellungen (abomination exhibitions) in Mannheim and Stuttgart in 1933 In a letter of July 21, 1933, Grosz wrote that he was secretly pleased and proud about this turn of events, because his inclusion in these exhibitions substantiated the fact that his art had a purpose, that it was true 9 The polemical articles about modern art, "art on the edge of insanity" as the official Nazi newspaper, the Volkischer Beobachter called it, also regularly included Grosz, with particular attention paid to his portraiture. A portrait of Max Hermann-Neisse, later to appear in the exhibition Entartete Kunst, was singled out for the "degenerate loathsomeness of the subject." A total of 285 of Grosz's works were collected from German institutions; five paintings, two watercolors, and thirteen graphic works were included in Entartete Kunst.

Grosz participated in an anti-Axis demonstration in New York in 1940 and revealed his reaction to the Führer in an interview with Rundfunk Radio in 1958:

When Hitler came, the feeling came over me like that of a boxer; I felt as if I had lost. All our efforts were for nothing.

Grosz returned to Germany permanently in 1958, somewhat disillusioned with his American interlude. He had wanted a new beginning and had tried to deny his political and artistic past, but he was appreciated in America primarily as a satirist, and the work from the period after the First World War was perceived as his best. The biting commentary that marked this early work was that of a misanthropic pessimist, not what he had become: an optimist infatuated with the United States. Grosz was unable to understand the American psyche to the degree that he had the German, and he returned to his homeland in an attempt to regain the momentum he had lost. He died in Berlin in an accident six weeks after his return.