It seems to be a stylistic choice amongst some major publications. The first time they say "President Foo", the second time Mr. Foo. From the Times directly: h

It seems to be a stylistic choice amongst some major publications. The first time they say "President Foo", the second time Mr. Foo. From the Times directly: https://www.nytimes.com/2017/11/08/reader-center/why-does-nyt-call-president-mr-trump.html https://www.nytimes.com/2017/11/08/reader-center/why-does-ny... And NPR discussing the same style for Obama https://www.npr.org/sections/publiceditor/2011/10/12/141293477/why-do-you-call-him-mr-obama https://www.npr.org/sections/publiceditor/2011/10/12/1412934...