The key differences between Marxism and capitalism in political theory are primarily centered on economic organization and class relations. Marxism advocates for a classless society achieved through the abolition of private property and the means of production collectively owned and controlled by the state. Conversely, capitalism is characterized by private ownership, market competition, and profit motive, where wealth and power are distributed unevenly among classes. While Marxism seeks to address inequalities and promote social welfare, capitalism thrives on economic growth and individual entrepreneurship, leading to inherently different political and social implications.