...Although that is only relevant if the law sez a President needs to be born a citizen, and some other law sez that being born a UFP citizen calls for being born into a species whose principal governing body is a UFP member at the time. These two laws have not been explicated in aired Trek, but they might have been explicated in written Trek. They do sound more than a tad racist, though.
Timo Saloniemi
It's a moot point, because the novels explicitly identify Bolarus as being a Federation Member, with Zife having previously served as Bolarus's representative on the Federation Council.