The most effective method for registering your opinion is by phone, then follow-up in writing by email on his contact form or by fax. Request a response.
Contact Form on Senate website (in lieu of email)
Washington D.C. Office
218 Russell Senate Office Building
Washington, DC 20510
Main: (202) 224-2235
Fax: (202) 228-2862
Arizona Offices
2201 East Camelback Road
Suite 115
Phoenix, AZ 85016
Main: (602) 952-2410
Fax: (855) 952-8702
122 North Cortez Street
Suite 108
Prescott, AZ 86301
Main: (602)952-2410
407 West Congress Street
Suite 103
Tucson, AZ 85701
Main: (520) 670-6334
Fax: (520) 670-6637