That said, several thinkers have had significant influence on modern-day leftists and their ideas. Some prominent figures include:
1. Karl Marx: Marx's ideas on class struggle, capitalism, and socialism have been foundational for leftist thought. His works, such as "The Communist Manifesto" and "Capital," continue to shape the understanding of economic and social inequality.
2. Michel Foucault: Foucault's work on power, knowledge, and the construction of social institutions has been influential among leftists. His ideas have been applied to understanding various forms of oppression and social control.