You can still get on base very easily. Mohammed Atta made 3 or 4 trips on base on the base tour bus. Pictures of him at the base were all over local TV right after 911.
In the 1980s when I was in, you couldn't get near ANY front gate of ANY military facility without the proper paper work. Then I became a defense contractor and that when I 'discovered' the policy change. Hell, you could even go right down pierside where the subs were.
Relaxing the rules was total insanity.