According to one housing expert, the U.S. real estate market could be headed for a troubling turn. Redfin CEO Glenn Kelman revealed what he believes to be the "real issue" that is paralyzing potential homebuyers during an appearance on "Cavuto: Coast to Coast.""Housing is just in a funk. Even though interest rates have dropped 20 to 30 basis points over the past few weeks, we've seen homebuyers still on the sidelines," Kelman explained during "Cavuto: Coast to Coast," on Wednesday.THE LEAST AFFORDABLE CITIE ...