Donald Trump really could be losing it, according to the ex-president’s nephew Fred Trump III. During a recent interview with Dean Obeidallah, he was asked about Donald’s mental fitness as concerns grow ahead of the 2024 election. “You know, you wrote about Donald’s father and your grandfather having dementia the last years of his life and that. Do you see anything? I’m going to ask you to be a doctor. Do you see anything in Donald now that reminds you of the grandfather during the times of dementia?” the host asked Fred during the Friday, August 16, edition of The Dean Obeidallah Show. “You k…