Modern habitual offender statutes, which trace their roots to eugenics-era policies, have created a system of selective incapacitation that exaggerates public safety benefits while contributing to mass incarceration. This paper argues that the "grossly disproportionate" threshold test fails to provide meaningful Eighth Amendment protections against lengthy sentences for adult, non-capital offenders. The result is a nationwide patchwork of proportionality standards for otherwise similar offenses. Utilizing California's "Three Strikes" law as a cautionary tale, this paper evaluates the harsh realities of Nebraska's mandatory minimums for repeat offenders, which eliminate judicial discretion and contribute to the prison overcrowding crisis. This paper advocates for legislative reforms in Nebraska, including eliminating mandatory minimums as a sentencing enhancement and creating judicial "safety valves" that allow for proper evaluation of mitigating factors.