Whether appellate waivers in federal criminal cases contain an implied exception for miscarriage-of-justice

QUESTION PRESENTED Petitioner Demonte Kelly pleaded guilty pursuant to a plea agreement that contained an appellate waiver. At sentencing, Mr. Kelly presented extensive, unrebutted evidence that he is intellectually disabled and requested a downward departure under United States Sentencing Guideline § 5H1.3. The district court rejected his argument based on an indisputably erroneous interpretation of the law and stereotypes about intellectual disability that this Court has repeatedly rejected. The Fifth Circuit denied relief, again refusing to adopt a miscarriage of justice exception to appeal waivers. The question presented is: Whether appellate waivers in federal criminal cases contain and implied exception for miscarriage of justice. i