When the newly enacted statute substantially changes the legal consequences of past events, it is considered to have retrospective effect. (Western Security Bank v. Superior Court (1997)) . Newly enacted legislation may operate upon preexisting matters, rights, or obligations, unless the law conflicts with a constitutional protection. (7 Witkin, Summary of Cal. Law (9th ed. 1988) Constitutional Law, 486, p. 675.) For example, a law that substantially impairs or deprives a person of a vested right will invalidly deny due process. (Ibid.) However, "a statute does not operate retrospectively simply because its application depends on facts or conditions existing before its enactment." (Western Security Bank, supra, 15 Cal. 4th at p. 243.) The Supreme Court further explained: "A corollary to these rules is that a statute that merely clarifies, rather than changes, existing law does not operate retrospectively even if applied to transactions predating its enactment. We assume the Legislature amends a statute for a purpose, but that purpose need not necessarily be to change the law. Our consideration of the surrounding circumstances can indicate that the Legislature made material changes in statutory language in an effort only to clarify a statute's true meaning. Such a legislative act has no retrospective effect because the true meaning of the statute remains the same. . . ' "An amendment which in effect construes and clarifies a prior statute must be accepted as the legislative declaration of the meaning of the original act.