What is the current state of the law on a defendant's right to choose his own counsel?

"[T]he essential aim of the [sixth amendment] is to guarantee an effective advocate for each criminal defendant rather than to ensure that a defendant will inexorably be represented by the lawyer whom he prefers." Wheat v. United States, 486 U.S. 153, 159 (1988) (citations omitted). While a district court must recognize a presumption in favor of a defendant's right to choose his own counsel, that presumption may be overcome by a demonstration of actual conflict or by a showing of serious potential for conflict. Id. at 164.