What is the case law on the basis of the majority finding that a search warrant is not necessary for the purpose of a protective sweep?

Finally, the majority relies on the police officers' expertise in cocaine cases, and suggests that because cocaine dealers tend to carry weapons and resort to violence, the suspicion of danger was justified. I cannot agree. The exigent-circumstances exception to the search warrant requirement mandates specific facts leading the police to fear for their safety. If the general fear that cocaine dealers are violent could fulfill this requirement, we essentially would create a cocaine exception to the search-warrant requirement. Our cases have not yet supported such a broad exception. See, e.g., United States v. Hatcher, 680 F.2d 438, 444 (6th Cir.1982) (finding in a heroin case that the protective sweep was not justified merely because the subject of drugs was involved and warning that this reasoning would "permit wholesale abrogation of the Fourth Amendment reasonableness requirement.").