Kamala Harris is a US citizen by virtue of Section 1 of the 14th amendment, neither of her non-citizen parent’s being a US citizen at the time of her birth. Her father was a legal immigrant from Jamaica, and her mother a lawful immigrant from India. I believe that both have naturalized has US citizens since then.
It is not possible, however to become a NBC retroactively, absent some extraordinarily corrupt court decision to the contrary. (which is a real possibility given the fact the courts at both the State and Federal levels repeatedly refused to grant certiorari to DOZENS of court challenges to Obama’s constitutional eligibility to be POTUS.)
Yah, I know the USSC rejected numerous cases on Obama. She will skate into the campaign without a glove laid on her. If trump is hot next year, she will wait till 2024.