So many first and second generation Americans are running for office, quickly getting bored with that and then running for president! So we have all this natural born crap that was unheard of when I first started voting.
I don't know when that was, but Baby boomers were taught "this crap" in our then respectable public school system.
Could be it was "unheard of" because everybody knew what it was, and nobody considered trying it.