All liberals might not be Marxists, but all Marxists are liberals. I don't know a single Marxist conservative.
Here's why (from the article):
Thus the endless dance of liberalism and Marxism, which goes like this:
1. Liberals declare that henceforth all will be free and equal, emphasizing that reason (not tradition) will determine the content of each individual’s rights.
2. Marxists, exercising reason, point to many genuine instances of unfreedom and inequality in society, decrying them as oppression and demanding new rights.
3. Liberals, embarrassed by the presence of unfreedom and inequality after having declared that all would be free and equal, adopt some of the Marxists’ demands for new rights.
4. Return to #1 above and repeat.
