If it is flying as Marine One, it CAN go anywhere its passenger wants to go. Its flight path is controlled so as not to be predictable. Depending on the 'code' onboard a military aircraft many rules and controls disappear.
There’s a difference between ‘fly anywhere’, which is what I said, and ‘go anywhere’, as you said.
Do you really think the pilot of Marine One is going to fly into harm’s way? He must remain in the restricted air space in D. C. unless under attack and needing to escape. It’s not even a close argument.
(If under attack, Marine One is far from alone in the air.)