You've mentored Nathan, an African American staff nurse who would be a valuable asset. As his mentor, you want to help him move on. Nathan loves his work and says that a supervisory position is "not for him." He serves on numerous committees, volunteers with local organizations, and seems to "know what's going on." You want him to think seriously about his career goals.
With such an excellent resume, you want to motivate him to make more of himself. He insists, "I just want to be a nurse. I'm tired of the expectation that I'd be a perfect role model for other minorities. Maybe I should pull back on my volunteer activities in order to get back under the radar."
Discussion
The purpose of a mentor is to help the person find out where his skills, talents, abilities, and interests lie. You've done a fine job mentoring him because he knows what he wants. You presented options and it's helped reinforce what he wanted to be.
My advice: stop. Hear what an employee in this position is saying and give that employee credit for knowing himself well. Affirm and celebrate this choice. In this case it's especially notable, because high quality nurses are a precious resource!
Managers need to take their judgment of employees out of the equation. It's not your responsibility or right to decide what someone will do for their life's work. Many people truly enjoy being the best nurses, aides, secretaries, doormen, teachers, technicians, and so on. They never want to go into management. It's because management wouldn't be where they find their joy.