I started a longish set of notes to moJoe
and realized that maybe one thing needs to be added here to "expand" Dworkin's language
in the quote given.
By my understanding, Dworkin is of the camp that sees gender as something "constructed" and therefore her definitions of "women" and "men" may not be entirely based on genital sex.
After all, biological "men" are sometimes rape victims, as are biological "women." To someone who frames gender in constructed terms, though, the act of being subject to rape either emasculates or feminizes the victim, whatever form of genitalia he/she may have.
For example, there are those who are raised as "women" whose sexual genotype is XY, but whose phenotype corresponds more closely to the generally accepted notions of woman/female/XX; there are likewise those raised as "men" whose genetic sex is XX, who possess a "male" phenotype. And there are variations aplenty beyond that, where the phenotype may be ambiguous in some way. Are these individuals men? Women? Both? Neither?
Socially, someone who is treated consistently as a woman or as a man, based on appearance, manner, and self-presentation, is, for most practical purposes, the sex people generally assume them to be. Or at least this so unless and until questions are raised or bureaucrats become involved.
This definition of human gender as a social construct may cast Dworkin's words in a different light. After all, her domestic partner of many years, John Stoltenberg, has written many books advocating "The End of Manhood," offering biological males, at least in theory, an out from a gender system that does tend to endorse a lot of what Dworkin has pointed out in many of her books, essays and speeches.
If gender is manufactured, not inborn, then you have the option of choosing (at least to some degree) not to be a "man" or a "woman." What is problematic, especially if you are someone who is identified by others as a "woman" — or as someone who in some way is "woman-like" — is that you find that, persistently and almost automatically you have become someone who is considered a "proper" subject of uninvited sexual attentions, and your choice and free will gradually (or suddenly, in some cases) become practically meaningless. At least, it's that context that I use when reading Dworkin.
Without that context, I agree that much of what she writes can come across as offensive, especially to those who feel they have no choice but to be "men" and who are accustomed to using that term rather carelessly in describing themselves and others.
(I typed this fairly impulsively, and plan to return to revise it. Please /msg me if you seek a better, clearer statement of anything I've said in my present sleep-deprived state.)