What is the current state of the law on the Eighth Amendment, the "narrow proportionality principle" that applies to sentences for non-capital sentences?

The Eighth Amendment to the United States Constitution prohibits cruel and unusual punishments and contains a narrow proportionality principle that applies to noncapital sentences. (Ewing v. California (2003) 538 U.S. 11, 20, 123 S.Ct. 1179, 155 L.Ed.2d 108 quoting Harmelin v. Michigan (1991) 501 U.S. 957, 996997, 111 S.Ct. 2680, 115 L.Ed.2d 836.) This constitutional right flows from the basic precept of justice that punishment for crime should be graduated and proportioned to both the offender and the offense. (

[202 Cal.Rptr.3d 834]