In People v. Wheeler (1992) 4 Cal. 4th 284 [14 Cal. Rptr. 2d 418, 841 P.2d 938], the Supreme Court considered what could be used as impeachment under article I, section 28, subdivision (d) of the California Constitution. Article I, section 28, subdivision (d) of the California Constitution states: "Except as provided by statute hereafter enacted by a two-thirds vote of the membership in each house of the Legislature, relevant evidence shall not be excluded in any criminal proceeding, including pretrial and post conviction motions and hearings, or in any trial or hearing of a juvenile for a criminal offense, whether heard in juvenile or adult court. Nothing in this section shall affect any existing statutory rule of evidence relating to privilege or hearsay, or Evidence Code, Sections 352, 782 or 1103. Nothing in this section shall affect any existing statutory or constitutional right of the press." The Wheeler court concluded that, subject to trial court discretion, any felony could be used for impeachment, as could a misdemeanor involving moral turpitude. (Wheeler, supra, at p. 296.) The Supreme Court emphasized that the underlying conduct of the witness should be used for impeachment; thus, a witness could admit the conduct or other witnesses could be called to describe the conduct. (Id. at pp. 284, 300).