Then he stopped using ecstasy, graduated from college, moved to Arizona, got a job in the construction industry, and then became a master carpenter in Colorado.

Gall struck a plea bargain with the Government, stipulating that he was responsible for the equivalent under the federal sentencing guidelines of 87.5 kilograms of marijuana.

The probation office also concluded (again, for sentencing purposes) that Gall was never an organizer or leader in the conspiracy, that his offense did not involve the use of weapons, and that he had no significant criminal history.

At the same time, while the Guidelines are one factor among many, they remain the product of empirical study of thousands of sentencing decisions over a quarter of a century.

Accordingly, while sentences that fall farther outside the Guidelines range must be justified with appropriate reference to the other factors, no "rigid mathematical formula" can dictate the precise extent of that justification.

Such a formula smacks of a presumption of unreasonableness for sentences imposed outside the Guidelines range, an approach the Court rejects and that the Government had conceded was inconsistent with Booker.

Such an approach is inconsistent with an abuse-of-discretion standard of review that the Court in Booker and again in Rita v. United States had held should apply.

Turning to the particular facts of this case, the Court commented that the district judge had committed no significant procedural error.

Justice Antonin Scalia reiterated his view that substantive reasonableness review was incompatible with the Sixth Amendment, but concurred out of concerns for stare decisis.

Justice Samuel Alito dissented because he believed that district courts should be permitted to give "some significant weight" to the Guidelines "in making a sentencing decision."

This belief flowed from his reading of United States v. Booker—a decision he did not participate in writing because it was issued before he joined the Court—because to fail to do so would ignore Congress's directive to not only "consult" the Guidelines but to "take [them] into account."

"It is unrealistic to think that this goal can be achieved over the long term if sentencing judges need only give lip service to the Guidelines."