San Diego, home of Camp Pendleton (1st & 5th Marine Divs.)
Marine Corps Recute Depot, Marimar Marine Air Base,
North Island Naval Air Station, Naval Station, San Diego-home of a major part of the Pacific Fleet, Naval Amphibious Base, San Diego Naval Hospital & Medical Center,
etc, etc, etc,
With the tens of thousands of military here, you don't get much more RED.
I vote for San Diego. :)