Final answer:
In Lockyer v. Andrade and Ewing v. California, the Supreme Court upheld life sentences under 'three-strikes' laws, which led to increased prison populations and higher costs.
Step-by-step explanation:
The rule established in Lockyer v. Andrade and Ewing v. California was that sentences imposed under the "three-strikes" law are not necessarily cruel and unusual punishment under the Eighth Amendment. As a consequence, these rulings upheld the constitutionality of long term sentences for repeat offenders, including life sentences for relatively minor crimes if they were the third offense.
The result of such enforcement of the three-strikes law often led to highly populated prisons and contributed to the rising costs of the incarceration system.