US v. Massenburg: Massenburg pleaded guilty to being a felon in possession of a firearm. Prior to sentencing, the probation officer concluded that he was an armed career criminal. At sentencing, Massenburg objected on Apprendi/Blakely grounds and also that the prior offenses were all part of the same course of conduct and should be counted as only one qualifying prior conviction. The district court disagreed and sentenced Massenburg to 210 months in prison.
On appeal, Massenburg raised a new argument - that he should be able to withdraw his guilty plea because he was not informed of the possibility of being sentenced as an armed career criminal. Although the court has found such a failure to require reversal in earlier cases, because Massenburg did not make an objection on the issue in the district court he was stuck with plain error review. Under that analysis, although there was error and it was plain, Massenburg could not show a "reasonable probability that, but for the error, he would not have entered the plea."