The 2010 Census Redistricting Data [P.L. 94-171] Summary File Technical Documentation can be accessed here

The 2010 Census Redistricting Data [P.L. 94-171] TIGER/Line Shapefiles are available for download from the U.S. Census Bureau's 2010 TIGER/Line products web page through the following URL:
http://www.census.gov/cgi-bin/geo/shapefiles2010/main

The technical documentation for the 2010 Census Redistricting [P.L. 94-171] TIGER/Line Shapefiles can be accessed here:

Questions or Comments pertaining to the P.L. 94-171 Summary File should be directed toward the following:
    Email: rdo@census.gov
    Call: (301) 763-4039

Questions or Comments pertaining to the TIGER/Line data portion should be directed toward the following:
    Email: geo.tiger@census.gov
    Call: (301) 763-1128