What are you asking me?
Discussion
An Afghan refugee has "European heritage" because her ancestors migrated from Europe 2000 years ago.
Does she get to "run America" under the "white nationalism" system you advocate?
No. I don't think a mexican illegal immigrant, a Haitian immigrant or an Afghan refugee should run America? Or any other majority white country. I don't see why that's crazy to see. I also don't think an Italian should run Nigeria or that an Englishman should run south Korea.
But you haven't answered the question of what, *legally* defines "white". In the way that excludes the Afghan refugee.
Or do we just pick a King based on ... Vibes?
Does Nigeria *legally* define black or Nigerian every time they select their leader? It's just not that good a question tbh.
No, but they have some legal system for deciding who becomes a President. An election, with eligibility criteria, etc. Same with Japan, or Europe, or any other advanced nation. And those nations don't have "racial" requirements.
Birthright citizenship, having one's family be in the USA for X number of years... etc. Those are possible criteria.