The Tenth Circuit has long held---as have other circuits---that a district court may consider acquitted conduct as relevant conduct at sentencing.
It's time to ask the circuits to reconsider. This week, the Michigan Supreme Court held that "due
process bars sentencing courts from finding by a preponderance of the evidence
that a defendant engaged in conduct of which he was acquitted." In People v. Beck (available here), the majority explained why this conclusion is not foreclosed by existing United States Supreme Court decisions. The majority also offered an impressive list of judges and commentators who have criticized the use of acquitted conduct at sentencing, including Justice Kavanaugh when he was on the DC Circuit (see here).
The Michigan decision was based not on the Michigan state constitution, but on the due process clause of the Fourteenth Amendment to the United States Constitution. Chances are good that the state will petition the United States Supreme Court for a writ of certiorari. Will the High Court bite? I don't know, but it won't hurt our clients to start preserving the issue (and it might hurt them if we don't).