In arguing to the jury, how have the courts treated comments made by the prosecutor in arguing?

As to the additional comments, we have carefully reviewed all remarks of the prosecutor in arguing to the jury. Some of the statements complained of are indeed unfortunate and unwise. The prosecutor would have been better advised to abbreviate his comments, avoid collateral matters, and concentrate on the evidence to be considered by the jury. Though comments of this type are unwise, at best, we do not believe that they rise to the level of error and, if error, were harmless beyond a reasonable doubt. Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967).