The first "three strikes"law, whereby a person convicted of a third felony is automatically sent to prison for life, was passed by the state of Washington in 1993. California followed suit a year later, spurred by uproar over the death of Polly Klaas, a 12-year-old girl abducted and murdered by a freed rapist. In all, 15 states have similar measures on the statute book, while Georgia plans to bring in an even stiffer "two strikes and you're out" law, effective from 1999, for certain offences.
Even the Federal Government - whose jurisdiction covers only 2 per cent of crimes committed in the US each year - has got into the act, with a "three strikes" proviso included in the Crime Bill passed by Congress in August 1994 and which has thus far affected some 20 cases.
Whether it is effective, however, is another matter. In California, where "three strikes" has been a hotter issue than anywhere else, Governor Pete Wilson claims it is a prime reason for two straight years of falling crime. Critics say that it merely distorts the judicial system and makes an already overloaded prison system even more unworkable.
According to one study by a San Francisco legal institute, the law hit twice as many marijuana smokers as rapists, murderers and violent criminals combined. In now famous California cases, convicts have recently been jailed for life after third offences of stealing two bicycles, and a slice of pizza. It also disproportionately affects African-Americans. "If you were writing a law to deliberately target blacks, you could hardly do it better than `three strikes'," one of the report's authors said last month.
Critics also claim that in the longer run, the measure will simply swell a national prison population of over 1 million, three times as large as in 1980, to the point where an ageing, long-term prison population will turn some jails into old people's homes. A surge in police killings in California, meanwhile, suggests "three strikes" has an unintended consequence of prompting criminals facing arrest to resort to extreme means to avoid what would otherwise be a life behind bars.
But for all its defects, the law is here to stay. Despite falling rates of violent crime in many states and big cities, law and order remains one of the hottest political issues in the US. Woe betide the candidate who argues for its repeal.