What is Althusser's role in New Historicism?

A New Historicist looks at how the individual writer writes but
also how the writer was influenced by his/her society and historical context; Point
A: including influences the author would not be aware of. Simultaneously, a New
Historicist must consider his/her own possible historical biases and must consider the historical
and cultural differences between, say, a 19th century Shakespearean critic from Jordan and a 20th
century Shakespearean critic from Mexico.

Althusser is a New
Historical-Marxist.  For him, identity is acquired through economic-social relations but also
through ideology. Althusser stated that we are "always already" subjects; subjected to ideology.
Ideologies, ideas and how to act (identity) are all material; they are rituals; subjects comply
with the production of their own identities. Hence, he talks about ISA's and RSA's (Ideological
and Repressive State Apparatuses), which like Foucault's panopticon, reinforce these identities.
Since subjects are 'always already' subject to being watched, they police themselves; they are
complicit in producing their own subjugated behavior.

The Marxist
tradition looked at how the individual would recognize his/her individual subjection to larger
social forces and this awareness of subjection would be emancipatory. But Althusser spins this:
subjects are individuals oppressed by social forces; but, subjects
are individuals produced by ideology and the relations of social forces and production. Their
awareness of subjection is not emancipatory; it is recognition and
reproduction.

So, just as social forces "hail" or produce subjects
though economic determination and social oppression,texts and novels produce subjects as well.
So, readers not only identify, relate or recognize themselves in characters and literature, but
are produced by them.

This is all part of New Historicism; that
history (social forces) and literature (all forms of writing) are interdependent. They write and
inform each other; and write and inform the subject (individual). And they do so by basically
saying, 'yes, this is us. These are our roles and identities. It may suck, but we're all in this
together. We are each individuals but subjected to social forces and there is comfort in
commiseration." The reader is not just empathizing; the reader is being addressed "hey, you feel
this way too." The reader's identity is not emancipated as in "oh, we are oppressed in that way;"
rather the reader's identity is being produced! "hey, you feel this way." Reader, "Oh, yeah, I
do."

And - Like Foucault's panopticon;
people police themselves because they are always already subject to being watched; always already
subject to ideology. So, bringing this back to Point A, Althusser
notes how the subject, like the author, may also be unaware of how he/she is producing his/her
own identity via the interdependent relations of writing, history
and society.

I guess his biggest contribution in this context was to
note the prevalence of ideology in art and literature as well; and to recognize that writing may
be ideological production disguised as liberating text/criticism.