Here are the addresses:
Bachmann for President
P. O. Box 96891
Washington, D.C. 20090-6891B

Herman Cain
Campaign Headquarters:
P.O. Box 2158
Stockbridge, Georgia 30281

Rick Santorum
PO Box 37
Verona, PA 15147

Romney for President, Inc., PO Box 149756, Boston, MA 02114-9756

Newt 2012
Post Office Box 550769
Atlanta, Georgia 30355

Here are electronic contacts:
http://www.mittromney.com/contact
http://www.newt.org/contact
http://www.hermancain.com/contact-us
info@michelebachmann.com
The only way to contact Rick Santorum is by mail.

I dont write Paul, Perry or Huntsman about illegal immigration.