“tak[ing] into account the totality of the circumstances.” Id. at 51, 128 S.Ct. 586. We presume a sentence within or below a properly calculated Guidelines range to be substantively reasonable. United States v. Sus, 674 F.3d 278, 289 (4th Cir.2012). Ramirez-Cortez asserts that the district court procedurally erred in determining that it lacked authority to vary downward on the basis of the sentencing disparities that result from selected application of the fast-track program. Ramirez-Cortez contends that the district court improperly concluded that it was bound by this court’s decision in United States v. Perez-Pena, 453 F.3d 236 (4th Cir.2006), because the Supreme Court’s subsequent decision in Kimbrough v. United States, 552 U.S. 85, 128 S.Ct. 558, 169 L.Ed.2d 481 (2007) (<HOLDING>), allows a district court to consider such a
holding that sentencing courts may vary  based solely on policy considerations including disagreements with the guidelines recognizing district courts ability to vary from guidelines based on policy disagreement with sentencing range in cases involving child pornography holding that a court of appeals may presume reasonable a district courts proper application of the sentencing guidelines holding a district court has authority to vary from the crack cocaine guidelines based on a policy disagreement with them italics omitted holding district courts are entitled to vary from the guidelines based on a policy disagreement with those guidelines