Apologies for tardy reply but I've been away from computer for much of last couple of weeks. It's been a good many years since I read Ryan but that's precisely why I mentioned him, his marxism & deconstruction book is almost two decades old.
As for what I think, I'm tempted to say that I agree with what Yoshie wrote on Ryan and be done with it, but I'll add that I also agree with Barbara Foley who distinguishes between marxism's historical subject - capital/labor relationship - located in material life and class struggles (social movement) and deconstruction's formalized, binary oppositions that elevate indeterminability to status of historical subject and block the possibility of resolution or synthesis. ('The Politics of Deconstruction,' _Rhetoric and Form_, 1985).
Both Foley and Peter Dews (_Logics of Disintegration_, 1987) show how class is elided in Ryan's and Spivak's focus on the margins (which is probably necessary at certain historical junctures). Moreover, R&S's antagonism to centralism is, in the long run, politically debilitating (in my view). Ryan's 'what is to be done' chapters actually pre-figure Laclau and Mouffe in positing a post(really anti)-marxist, left-pluralism. And if memory serves, Nancy Fraser (can't recall name of book right now) refers to efforts to link politics and deconstruction as resulting in apolitical liberalism.
Bryan Palmer's (_Descent into Discourse_, 1990) investigation of the relationship between historical materialism and discourse is illuminating. He distinguishes between dialectical approaches that offer opportunities to engage in a dialogue about the two and those that, in reifying language, deny/displace the former.
In any event, I've yet to participate in a political action or group where someone told me that they were involved because they'd read or practiced deconstructive literary criticism or post-stucturalist social theory (which is not to say that such are devoid of utility or have had no influence on some folks' politics, including my own).
For whatever above is worth, Michael Hoover (whose use of decade old and older references is sign that I don't read much of this stuff anymore)