Not sure if you received this posting, but it might be a good starting point:
The Supreme Court of Texas seeks summer, full-time interns for unpaid internships. Interns focus primarily on the preparation of memoranda concerning Petitions for Review. Work on the memoranda is supervised by the staff of each Justice. Once editing is completed, the memoranda are circulated to the entire Court for disposition.
A separate cover letter, resume, unofficial transcript of grades and writing sample should be provided for each justice to whom application is made. These may be mailed directly to one or more justices at P.O. Box 12248, Austin, TX 78711. Information about individual justices is available at www.supreme.courts.state.tx.u s