Because his mother lives in Turkey she has Alzheimer’s and she refuses to come to the United States. That’s why he is not renounce his Turkish passport.
That sounds like a valid reason.
Except it will still be a reason if he elected.
When you run for office, you need to decide what are your priorities.
I don’t believe it it is a good look to have dual citizenship and run.
He can't visit his mom with a US passport?