I’ve heard that before, but I’ve also heard that Kennedy’s phrasing was acceptable depending on context- I’ve been led to understand that “Ein Berliner” is more ambiguous as it could mean either a delicious doughnut Or a person from Berlin, whereas “Ich bin deutsch” is less ambiguous- but the context was clear, so from what I’ve heard (from German speaking people), German speaking people did not think he was calling himself a doughnut.
Upon looking a few other things up, I have also learned that the indefinite article is generally omitted when a person from Berlin is talking about their actual place of residence, but for the way JFK was using the term- in a figurative sense- that was actually the correct phrasing. Additionally, Berliner is commonly used as a word for doughnut in the north, west, and southwest of Germany, but not in Berlin itself, there you’ll more commonly hear “Pfannkuchen.” (Although Google Translate will tell you that means “pancake”).
When JFK initially said this phrase, there was some laughter shortly thereafter- but that was because he initially mangled the pronunciation and made a joke thanking his interpreter for translating his German. Once he said it correctly, he got cheers and applause. No one was confused because the context was clear- he’s not really from Germany, he’s speaking figuratively, and this actually is the correct way to call oneself a Berliner in a figurative sense that speaks to solidarity.
For anyone who thought my initial comment was a little bit strange- I posted a link about a massive amount of support in St. Louis for bringing Syrian refugees to that city. I recalled how in recent weeks Germany, and most especially the city of Berlin, has done a wonderful job of welcoming tens of thousands of refugees into their homeland. Then I made a reference to the JFK thing, suggesting that these people from St. Louis might be feeling a sense of solidarity with Germany right about now. Which is not to say they are actually from Germany, but figuratively speaking, they respect this openness and generosity while seeking to stand with them by welcoming thousands of refugees as they are doing.
With that being said- a jelly filled doughnut sounds delicious right about now.