Compound interest is a very powerful force in finance. (Whether Albert Einstein really declared it to be the most powerful force in the universe is undetermined.) But if you choose crime as your career instead, you may run into a different kind of compounding: recidivist sentencing enhancements.

The Armed Career Criminal Act (ACCA) provides additional time for criminals with prior convictions for "violent" crimes and for "serious" drug offenses. What is "serious"? Well, Congress said that if the maximum sentence for the offense is 10 years or more, that's serious. Gino Rodriquez had two priors for burglary, which Congress has declared to be "violent." Then he had a case with three drug offenses, committed on separate occasions but adjudicated together. Under the relevant state law, the offenses were punishable by up to five years, but that could be doubled if the person was convicted of more than one, whether previously or concurrently.

So are these drug priors "serious" within the meaning of the ACCA? The Supreme Court said yes, 6-3, in today's decision in United States v. Rodriquez, No. 06-1646. The majority went with the plain meaning of "maximum term." If Rodriquez had asked his lawyer on the prior occasion, what is the maximum term, the lawyer would surely have included the doubling statute in answering the question. The dissent would apply the rule of lenity to include only the max for the base offense, not recidivism enhancements.

Here is the compounding effect. Rodriquez's multiple offenses exposed him to a risk of 10 years on the prior occasion, although he only got 4, concurrent. That exposure then elevated those same offenses to "serious" ones in his subsequent federal case. Should we wring our hands over this? I don't think so. Although President Bush has said that America is the land of the second chance, a seventh chance is a bit overboard. This guy has demonstrated that he has no intention whatever of ever going straight. Locking him up for the next 15 years means 15 years that he will not be committing crimes on anyone on the outside.