the epistemic dimensions of struggles that are primarily political? How can such struggles be understood as involving collective struggles for epistemic recognition and self-determination that seek to improve practices of knowledge production and make lives more liveable?
conceptualizing the harms and wrongs of epistemic injustice relationally, and by explaining epistemic injustice as rooted in the oppressive and dysfunctional epistemic norms undergirding actual communities and institutions
Epistemology pertains to the theory of knowledge. An "abusive epistemic relation" or dimensions thereof would describe efforts to manipulate knowledge to take advantage of someone else. Both of these passages talk about justice, politics, and epistemology, which is an intersection of primary concern in philosophies of critical theory.
Both quotations speak to the fact that one group of people can manipulate another group of people politically, with disenfranchisement for example by crafting knowledge, perhaps through propaganda, to get one group of people to willingly or grudgingly accept the subjugation of another.
Dominance hierarchies are the norm among animals, and human beings are no exception. History is one long reading of how one group of people take advantage, generally of labor or taking resources, of another. This is much easier if the dominant group crafts the thinking of the dominated. Domination can occur in extremes like genocide, slavery, and rape, but it can be much more subtle, like bias in zoning laws, unfair forms of taxation, and bias in history and education. The reality about the imbalance of power structures is that they are often maintained by manipulating peoples' knowledge and theory of knowledge. In Marxism, the term false consciousness is often used to describe a collective view of the world wherein the disadvantaged often believe and support the very system that takes advantage of them. Some serfs willingly supported their lords, some workers accept indecent working conditions, and some slaves support the institution, not because they don't have the means of confronting the power imbalance, but because they believed or believe in some sort of natural order. The Great Chain of Being had political overtones, for instance.
US history is one of a progression of increasing liberalization. The 17th century here in the modern US started off with a lot indentured servitude and slavery. These systems worked because people broadly accepted the "knowledge" of inferiority and superiority of races. The Holocaust was built on the premise that one race was threatened by another race which would have been an acceptable premise during the 1939 Nazi rally in New York City! Here in Chicago, the US labor movement helped to better the working conditions by advocating for collective bargaining spurred on by exploitative labor practices, like those documented in Upton Sinclair's The Jungle. Today, slavery, child labor, and abusing workers are rejected in all fifty states legally, and sufferage is near-universal, though restriction on voting rights is on the rise.
Slavery and child labor are obvious examples. Sometimes imbalances in power structures are subtle and need to be called out. As part of Marshall McLuhan's quotation "The medium is the message," consider how technologies of communication can be used to manipulate people's knowledge of the world:
In Understanding Media, McLuhan describes the "content" of a medium as a juicy piece of meat carried by the burglar to distract the watchdog of the mind.12 This means that people tend to focus on the obvious, which is the content, to provide us valuable information, but in the process, we largely miss the structural changes in our affairs that are introduced subtly, or over long periods of time.13 As society's values, norms, and ways of doing things change because of the technology, it is then we realize the social implications of the medium. These range from cultural or religious issues and historical precedents, through interplay with existing conditions, to the secondary or tertiary effects in a cascade of interactions that we are not aware of.13
This is also a major theme of Noam Chomsky and his partner Herman in Manufacturing Consent:
It argues that the mass communication media of the U.S. "are effective and powerful ideological institutions that carry out a system-supportive propaganda function, by reliance on market forces, internalized assumptions, and self-censorship, and without overt coercion", by means of the propaganda model of communication.1 The title refers to consent of the governed, and derives from the phrase "the manufacture of consent" used by Walter Lippmann in Public Opinion (1922).2 The book was honored with the Orwell Award.
In summation, your worldview is to a large extent what your theory of knowledge, your epistemic practices create. All of us are born without critical thinking skills, are defenseless against religious indoctrination, and are subject to the will of our societies from the moment we are born. Berger and Luckmann in the 1960s put forth a book The Social Construction of Reality that attempts to create an epistemic theory to catalog those mechanisms in society that guide the manufacture of knowledge and roles and led to the social philosophy of social constructionism. We are inescapably members of our culture, we use its language and have social transactions in its institutions. We are products of collectivized knowledge to the extent we don't try to rewrite our own. An ancient Roman plebian believed he was a plebian. A member of a cult likewise defers to the reality of the cult leader. While these social forces aren't the only forces, they exert a great force on who we are, and whether or not we are taken advantage of. So any producer or product of knowledge, Newspeak for example, has epistemic dimensions.