Does the narrow proportionality principle of the Eighth Amendment apply to non-capital sentences?

"The prohibition against cruel and unusual punishment encompassed in the Eighth Amendment contains a 'narrow proportionality principle' that 'applies to noncapital sentences.' [Citations.]" (Ewing, supra, 538 U.S. at p. 20, citing Harmelin v. Michigan (1991) 501 U.S. 957, 996-997.) " 'The Eighth Amendment does not require strict proportionality between crime and sentence. Rather, it forbids only extreme sentences that are "grossly disproportionate" to the crime.' [Citation.]" (Ewing, at p. 23.)