The issue in People v. Mendoza (1998) was whether evidence of voluntary intoxication is admissible on whether a defendant tried as an aider and abettor had the required knowledge and intent. (People v. Mendoza, supra, 18 Cal. 4th at pp. 1123, 1126.) The court concluded the intent requirement for aiding and abetting liability is a " 'required specific intent' " for which evidence of voluntary intoxication is admissible under section 22. (18 Cal. 4th at p. 1131.) However, the court cautioned: "Our holding is very narrow. Defendants may present evidence of intoxication solely on the question whether they are liable for criminal acts as aiders and abettors. Once a jury finds a defendant did knowingly and intentionally aid and abet a criminal act, intoxication evidence is irrelevant to the extent of the criminal liability." (Id. at p. 1133; see also Ginns v. Savage (1964) 61 Cal. 2d 520, 524, fn. 2 [39 Cal. Rptr. 377, 393 P.2d 689] ["Language used in any opinion is of course to be understood in the light of the facts and the issue then before the court, and an opinion is not authority for a proposition not therein considered."].) It is clear that the effect of the 1995 amendment to section 22 was to preclude evidence of voluntary intoxication to negate implied malice aforethought. As explained in People v. Reyes (1997) 52 Cal. App. 4th 975, 984, footnote 6 [61 Cal. Rptr. 2d 39]: "As part of the 1995 amendment to section 22, subdivision (b), evidence of voluntary intoxication is no longer admissible on the issue of implied malice aforethought . . ., thus superseding the holding of People v. Whitfield. However, the court's analysis remains germane to the admissibility of evidence of intoxication to refute the element of knowledge in other types of crimes, such as receiving stolen property." Relying on the dissenting opinions in Montana v. Egelhoff (1996) 518 U.S. 37 [116 S. Ct. 2013, 135 L. Ed. 2d 361], defendant argues that section 22 unconstitutionally removes a relevant category of evidence--the defendant's mental state--from the jury's consideration. Defendant maintains section 22 prevented her ability to attack an element of the offense (i.e., implied malice) in violation of her due process rights. Defendant's analysis is flawed. The due process clause precludes a conviction unless the state has proved beyond a reasonable doubt every fact necessary to constitute the crime with which the accused is charged. This burden cannot be shifted to a defendant. (Patterson v. New York (1977) 432 U.S. 197, 204-205 [97 S. Ct. 2319, 2324, 53 L. Ed. 2d 281].) Thus, "the Due Process Clause requires the prosecution to prove beyond a reasonable doubt all of the elements included in the definition of the offense of which the defendant is charged." (Id. at p. 210 [97 S. Ct. at p. 2327].)