He’s not being “used” by the establishment. He’s running for president and some people like him.
Carson will gain more popularity with liberals and those who enjoy race baiting when the National Review interview with him from April is more widely read. He said he and AL Sharpton share the same goals. 7 years of race baiting isn’t enough I guess.
Those aren't mutually exclusive, not at all. The establishment is opportunistic, and will take advantage where it finds it.