Can Police Pat Me Down or Search Me If I Haven't Done Anything Wrong?

Unfortunately, the short answer to this question is yes, as it seems that Tennessee Courts continue to erode the protections of the State and Federal Constitutions.
It is well settled law that an officer can perform a frisk, often called a protective search, of a suspect when the officer has "reasonable suspicion" that the suspect is armed. See Terry v. Ohio, 392 U.S. 1 (1968). Reasonable suspicion must be based on "specific and articulable facts," not just "inchoate and unparticularized suspicion or 'hunch.'" Id. According to the Tennessee Court of Criminal Appeals, these specific facts may be derived from information obtained from other law enforcement personnel or citizens, known patterns of criminal behavior, or the officer's experience. State v. Winn, 974 S.W.2d 700, 703 (Tenn. Crim. App. 1998). The Winn Court further states that "other circumstances" may justify a protective search, including:

[A] characteristic bulge in the suspect's clothing; observation of an object in the pocket which might be a weapon; an otherwise inexplicable sudden movement toward a pocket or other place where a weapon could be concealed; an otherwise inexplicable failure to remove a hand from a pocket; backing away by the suspect under circumstances suggesting he was moving back to give himself time and space to draw a weapon; awareness that the suspect had previously been engaged in serious criminal conduct; awareness that the suspect had previously been armed; [and] discovery of a weapon in the suspect's possession.

Id. at 704 (quoting LaFave, Search and Seizure, § 9.5(a) (3d ed. 1996 & Supp.1997)).
Ultimately, a court is going to look at the totality of the circumstances to determine the legality of a protective search of an individual who is not under arrest. However, if the protective search is valid, then one other doctrine, the "Plain Feel Doctrine," may expose the individual being searched to even further invasion.
Under the Plain Feel Doctrine, police can seize contraband from a suspect if three conditions are met: (1) a prior valid reason exists for the protective search; (2) the contraband is detected while the protective search is legitimately in progress; and (3) the incriminating nature of the object perceived by the officer's sense of touch is immediately apparent, which ultimately gives the officer probable cause to believe the object is contraband. Minnesota v. Dickerson, 508 U.S. 366, 374-75 (1993). Probable cause that an object is contraband exists when the officer's knowledge of the facts and circumstances, considering the totality of the circumstances, would lead a person of reasonable caution to believe that the object may be contraband. Texas v. Brown, 460 U.S. 730 (1983).
Knowing this, can the police pat you down or search you when you have done nothing wrong? Under the right circumstances, yes they can. If police see an individual with an extensive criminal history that has a significant bulge in his pocket, then they may be able to legally pat him down even though he has done nothing wrong. In the end, whether or not such a pat down or protective search is legal depends on the facts of each case. Sadly, courts have added more and more exceptions that allow the police to search individuals who have done nothing but look suspicious to the police