There are lots of scientists working with adult stem cells. Many of those have been highlighted here at FR. This is not why he's being denied tenure. It's because his work is not particularly good by comparison to all of those others who are out there working with ASC. He lost my support when he turned this into a racial issue, which it is not. There are lots of non-whites with tenure at MIT.
How do you know that?
Do you know of any other scientists at MIT in the same situation?
(who only work with adult stem cells?)
It probably is not racial as much as political. But most of what you say sounds like pure speculation. There is no way you could know about his work and provide and evaluation of such unless you had inside information or was on the review board.