No, not Karl Marx, but the Marx brothers! Raymond Geselbracht wrote an article on “The Correspondence of Harry Truman with Groucho and Harpo Marx,” in Prologue Magazine.
Harry Truman loved vaudeville theatre from the time he was a teenager. But Truman’s association with the Marx Brothers didn’t stop with theatre shows and it went much deeper than comedy. In the spring of 1945, Groucho Marx sent President Truman a letter:
When Truman became President in the spring of 1945, one of the first problems that came to him was what to do about the survivors of the Holocaust who were living in displaced persons camps in Europe. He had great sympathy with the displaced persons, and he issued a directive in late 1945 intended to allow some of them to immigrate to the United States. Among the many Americans who were concerned about the displaced persons and were following Truman's actions with regard to them was a former vaudevillian whom Truman certainly remembered. On October 8, 1946, Groucho Marx sent Truman a clipping of a Life magazine editorial, "Send Them Here! Europe's Refugees Need a Place to Go and America Needs to Set a World Example." The article claimed that Truman's attempt to help displaced persons to immigrate to the United States had failed. "In God's name[,]" the editorial concluded, "can we go on doing nothing about these DPs?" Groucho asked Truman to consider the article. "I am sure that you are deluged with mail of this sort," he wrote, "but even a president at times can be confused." He added a PS: "Despite all this I propose voting for you in 1948."
Their correspondence, even when Truman was in office, wasn’t completely serious as this letter from Harpo shows:
Harpo contacted Truman a little less than a year after their meeting at the air base. There was much speculation at the time whether Truman would run again in 1952, and Harpo thought he had a good idea. "If you don't run in 1952," he wrote, "how about Margaret? I could swing a lot of votes."9 "I think that is a very important question about 1952," Truman responded, not willing to give anything away regarding this very sensitive matter. "At a later date I will be glad to discuss the matter with you."
The article sums up the friendship:
Truman felt the allure of the Marx Brother's zany view of life from the time he was a young man, and he never forgot or renounced it. His memories of the Marx Brothers' riotously irreverent attitude to authority and to all the people and institutions that embodied it might well have contributed to the remarkable humility that he maintained during all the time he held high office. His youthful encounter with the Marx Brothers certainly encouraged him to recognize, as he always did, that life, among its other mysteries, is fundamentally humorous.
For the Marx Brothers, on the other hand, Truman was the President whose heart was rightly positioned on the refugee issue after World War II and who recognized and supported Israel. Though it is not recorded in the correspondence in the Truman Library's holdings, they must have recognized that Truman felt strongly the need to bring social justice to all Americans and to bring what was best in American life to people all over the world. In any event, Groucho voted for Truman the only time he could, in 1948, and would have voted for him again; one thinks the same is true of Harpo.