Helot on Wheels

'The U.S. Constitution and the constitutions of the various states purportedly offer ironclad, black-letter protection against unreasonable searches and compelled self-incrimination. Yet any American who operates an automobile may be stopped at any time by a uniformed tax-feeder and compelled to undergo a blood test -- if the donut-grazer in question affects to believe that the driver is intoxicated, whether or not there is evidence to support that belief.'