Mandatory minimum sentencing laws require courts to impose a predetermined minimum prison sentence when a defendant is convicted of a specified offense. Judges cannot impose a shorter sentence even if mitigating factors exist. Congress established many federal mandatory minimums during the 1980s and 1990s War on Drugs and crime-fighting legislation, including the 25-year consecutive sentence for second or subsequent firearm convictions under 18 U.S.C. §924(c). Critics argue mandatory minimums eliminate judicial discretion and produce disproportionately long sentences; proponents argue they deter crime and ensure consistency.