“As for practice, your arguments do *nothing* to explain why *both* Chester Arthur and Barack Obama took pains to hide their formal legal status as children of non-US-citizen parents.”
That’s just nuts. Barack Obama wouldn’t shut up about his Kenyan father. He wrote a freekin’ book about it. His first major speech to a national audience was his 2004 Keynote at the Democratic National Convention. After the thank-yous, the speech began, “Tonight is a particular honor for me because, let’s face it, my presence on this stage is pretty unlikely. My father was a foreign student, born and raised in a small village in Kenya.”
Everyone but cave-dwellers knew Obama’s father was a foreigner. And the Chief Justice of the United States swore him in as our 44’th President (twice!).
You missed the key word I wrote: “legally.” From the legal perspective, Obama’s legal father was/is as good as hidden in plain sight since there is no legal leverage to get legal confirmation. Without legal confirmation, his father’s citizenship is of no legal value to anyone in the court system, and Obama relies on the reliably socialist mainstream media to protect him from everything else.