Under Federal Rule of Criminal Procedure 52(b), a court of appeals “should exercise its discretion to correct”  an error in the district court’s application of the Sentencing Guidelines if the error “seriously affects the fairness, integrity, or public reputation of judicial proceedings.” In Rosales-Mireles v. United States, after the defendant was sentenced under a miscalculation under the Sentencing Guidelines and raised a Rule 52(b) request on appeal, the Fifth Circuit declined to afford relief because the result (which was within the correct Guidelines range) did not affect the mentioned factors, nor did it “shock the conscience.” The Court, in a 7-2 decision authored by Justice Sotomayor, reversed, holding that a correction under Rule 52(b) is required almost every time a plain error affecting the defendant’s established rights occurs, unless some “countervailing factors” compel a different result. Justice Thomas, joined by Justice Alito, dissented, arguing that plain error review should only permit relief in exceptional circumstances, and not establish a “rebuttable presumption” as the majority has ruled.