Odets wrote Waiting for Lefty during his time with the Communist Party, crafting it as propaganda to support a socialist revolution in America, akin to the Russian Revolution on November 6, 1917. Since Marxist theory, based on Karl Marx's Communist Manifesto, focuses on economic struggles between social classes, it's almost unavoidable that the play is intensely "class-conscious." Characters are clearly divided by class, depicted in stark opposition: on one side stand the virtuous and enduring working class, and on the other, the greedy and ruthless capitalists who exploit them. Although the settings and dialogues in Scenes I ("Joe and Edna") and III ("The Young Hack and his Girl") are realistic, the larger conflict between "workers" and "capitalists" is portrayed in stark, simple terms. The antagonist Harry Fatt is a hyperbolic stereotype, and even the noble workers are almost caricatures in their unyielding virtue.

This approach might seem overbearing to modern viewers, possibly causing them to view the work as unrealistic. However, given its specific, highly political objectives aimed at a particular historical period, it might be unjust to evaluate Waiting for Lefty using standard critical criteria. Odets sought to bring Marxism—a theory often hampered by technical language and abstract ideas—to life. The theory's logic is based on the "dialectic," a dynamic of opposing forces, particularly the classes of Capital and Labor.

Odets translates Marx's theories into personal experiences, replacing abstract concepts with the harsh realities of human lives. As Dr. Benjamin (a role Odets himself played in early performances) declares, "you don't believe theories until they happen to you." The playwright demonstrates theory unfolding in people's lives as characters come to realize that their suffering has been orchestrated by the "bosses" and "money men." Individually, they are powerless, but collectively—acting as a class against those in power—they can achieve triumph.

The wide range of characters and the various paths they take to the strike meeting cross many traditional class boundaries. For example, impoverished blue-collar workers like Joe and Sid are often viewed as existing in a completely separate world from salaried, relatively privileged professionals like Dr. Benjamin or the lab assistant Miller. Yet, they are all part of the strike committee, and the union is likely strengthened by the blending of their skills and backgrounds, with different classes working together. Had Miller and Dr. Benjamin continued to serve their capitalist employers, they would have remained "class enemies" to the workers. However, their experiences have led them to realize that they are just as affected by the manipulations of power as the working class; their interests are linked with those of "common laborers." They have come to understand that their true loyalty lies with "the people," surpassing any personal differences among comrades.

The diverse range of "types" in the narrative increases the chance that each audience member will connect with at least one character. Since every character's story points to the same class-based enemy, the specific character with whom one identifies becomes less significant. Together, their stories highlight the numerous subtle ways the system sustains itself and exploits those who rely on it for their survival. The characters' collective determination overshadows their differences; unity against the capitalist class becomes more important than any personal allegiances, including self-interest (like the prestige and wealth Miller turns down) and even family ties (such as the "lousy" brother Clancy who is revealed as a strike-breaker).

Marx posits that class struggle is the core element of economic life, and Odets adopts this as a central theme, although his approach is notably distinct. By the time Agate Keller asks, "Well, what's the answer?", the play's logic allows for only one possible response. The individual reader's or viewer's reaction to the play largely depends on our answer to another question: "Which side are you on?"