It's not unreasonalbe to ask. But there's no requirement that he do so. So unless enough people care to get him voted out of office, it isn't going to matter. And clearly most Americans don't care.
Sorry, I was being polite. It was not unreasonable for State Election officials to DEMAND that he establish his proof of citizenship since he himself called it into question. And yes, there is a requirement that he do so. It is implicit in the law which establishes qualifications.
So unless enough people care to get him voted out of office, it isn't going to matter. And clearly most Americans don't care.
Apathetic and Ignorant is no way to go through life. Most Americans wrongly expect their elected officials to handle this election stuff without their input. It never occurs to anyone that they should question that the election officials are doing their jobs properly unless they have a blatant examples of corruption or incompetence, and sometimes not even then.