How have the courts treated counsel's closing argument in closing arguments?

2 The court instructed the jury that "counsel's remarks, statements and arguments are intended to help you understand the evidence and apply the law. They are not evidence, however, and you should disregard any remark, statement or argument which is not supported by the evidence or the law as given to you by the court." Instruction 1. The prosecutor opened his closing argument by telling the jury "anything I say to you at this point or later, and anything that the defense tells you, is not evidence in the case." Verbatim Report of Final Argument at 2. Cf. Donnelly v. DeChristoforo, 416 U.S. 637 (1974) (noting mitigating effect of such curative instruction).