You do not directly address former Presidents of the United States as "Mr. President." You may refer to them as "former Presdient So-and-so" in the context of their time or actions in office, but they do not retain the title. If we take this as a convention that would be carried forward to the 23rd century, it is acceptable that Archer be referred to as Admiral even if he was once Federation President.
The entire staff of the radio station where I work were schooled in this etiquette by Governor Carter's staff in advance of his visiting to appear on our morning talk show.
Further citations:
From protocolconsultants.com:
"Head of State" in the USA is a Governor or the President. A leader in another country might be a president, prime minister, etc.
How to address a FORMER head of state:
- Senators and Governors would retain their titles.
- House of Representatives would be "Mr./Ms."
- Heads of State - each embassy/country, may be different. Contact specific embassy.
- all others including presidents, do not retain their titles; they are "The Honorable" or in person "Mr./Ms."
From the Boston Globe's Peter Post:
Q: I'm unhappy when I hear former presidents and other ex-officials addressed as ''Mister." Doesn't this belittle their importance? I was taught to address people with the highest title or position they've achieved in their career.
W.P., Chelmsford
A: You've waded into the quagmire of what's ''proper" here, so bear with me. When addressing a former president of the United States in a formal setting, the correct form is ''Mr. Last Name." (''President LastName" or ''Mr. President" are terms reserved for the current head of state.) This is true for other ex-officials, as well.
When talking about the person to a third party, on the other hand, it's appropriate to say, ''former president Last Name." This holds for introductions, as well: A current state governor is introduced as ''Governor Tom Smith," while you'd introduce an ex-governor as ''former Governor Jim Bell."
Now, let's wade a bit deeper. In an informal setting (such as a private lunch), it's acceptable to use the title the ex-official held. Here, you could refer to former president Jimmy Carter as either ''President Carter" or ''Mr. Carter."
Finally, if the person you're lunching with held more than one previous position -- say, judge and ambassador -- you'll want to know which title he or she prefers.
From Judith "Miss Manners" Martin:
The rule is that there is only one president of the United States at a time; therefore, the title does not accompany anyone out of office. Many lesser titles do, however, so a
former president generally uses his last such title. The proper address is Senator Nixon, as it is Governor Reagan and Governor Carter.
