Feminism is the same thing as marxism because they both have the same goal of denying the differences between people. Marxism is very broad while feminism is very narrow. Feminism only focuses on making men and women the same despite their inherent differences. This is marxism. Anything that seeks to make on thing the same as another thing when those two things just have inherent differences is marxism.
Feminism is not about making sure that women's inalienable rights are not infringed upon by the government or by other private citizens, that is what is known as 'first-wave feminism'. Feminism today is about tearing down the inalienable differences between men and women, which is, of course, impossible because they are inalienable. You cannot lose what is inherently, inalienably yours. (definition of inalienable: 'Unable to be taken away from or given away by the possessor.') Freedom of speech is inherently yours and your 'possessory interest in freedom of speech cannot be taken away, it can only be hindered. Just because someone does not allow you to speak does not mean that you do not have the 'right' to speak. In the same way, the differences between men and women are inalienable. No matter how much the progressive left tries to legislate policy that denies the differences between men and women, there are differences.
When the left tries to say that women should be allowed into combat roles in the military, they are denying the basic differences in the biology of men and women. This is marxism. Marxism is all about creating a classless society. When there is a societal difference between men and women, that creates a 'class'. It creates a difference between two groups of people therefore you cannot have marxism where you have a society that recognizes the inalienable differences between men and women.