Critics say that The Great Gatsby by F. Scott Fitzgerald symbolises the corruption of the American dream. For example, Charles R. Hearn:
Fitzgerald emphasizes the fact that the content of Gatsby’s dream is materialistic and corrupt. Like Dexter, Gatsby has a goal beyond material success, but that goal itself (Daisy) is symbolic of shallow, materialistic glitter. [...] Gatsby’s method of realizing his dream is no less corrupt than the content of the dream itself. He cannot even be given credit for the open and honest ruthlessness of the robber baron of a generation before him; his fortune has come from bootlegging, gangsterism, and unexplained shady deals.
Charles R. Hearn (1977). The American Dream in the Great Recession, p. 44. Westport, Connecticut: Greenwood Press.
But how can the American Dream be corrupt? It is merely a concept, an ideal. What do critics like Hearn mean when they say this in relation to The Great Gatsby?