ZeroBugBounce found the link to the source of this text, which enables us to consider it in context:
When it comes to the real war on woman – which includes sentencing those who opt to becomes Christians to death and shooting little girls in the head who want nothing more than to go school to become educated in math, science, languages and the humanities, then we don’t hear so much. So shame on all the liberals – including the ones who are my bloleagues here on Thomas Jefferson Street – who rail quite eloquently against the disproven idea that the disparity between what women in the workforce make compared to men is only because the system is patriarchal and sexist, but who had nothing to say about a lone woman, a mother of two, languishing in a Sudanese prison solely because of who and how she chose to worship.
So this is just a poorly constructed sentence. As written, the author appears to claim that there exists an idea that gender wage disparity is due to patriarchy and sexism, and that liberals rail against that idea--i.e., that liberals believe that gender wage disparity is not due to sexism and patriarchy. That's backwards. Liberals don't rail against that idea, they embrace it as representing the truth--and it is that truth, as they perceive it, that they deplore.
What the author should have written was:
So shame on all the liberals ... who make the disproven claim that the disparity between what women in the workforce make compared to men is only because the system is patriarchal and sexist....
(note: I offer no defense of the sentiment expressed here; I merely point out how it could have been made clearer.)