Nearly 5,000 people below the age of 21 die because of excessive alcohol consumption each year. Oddly, this has triggered a new movement to lower the drinking age. In America, young people can vote, drive, marry, divorce, hunt and go to war before alcohol is legally allowed to touch their lips. Many states once set their minimum drinking-age at 18. But in 1984 Ronald Reagan oversaw the passage of the "21 law", which requires states to set 21 as the minimum drinking-age or risk losing 10% of their highway funds. Now campaigners want to move it back. In the past, states have been too financially timid to challenge the 21 law. But calls for change are growing louder. Two local judges in South Carolina recently ruled that banning 18- to 20-year-olds from drinking or possessing alcohol is unconstitutional. Public officials, including the former attorney general of South Dakota, have called the 21 law a failure. The about-face of Morris Chafetz, a doctor who served on the commission that recommended increasing the drinking-age to 21, has also raised eyebrows. This week he called it the most regrettable decision of his career. Supporters of existing status, including the organisation Mothers Against Drunk Driving, say that the law has helped avoid thousands of deaths. But doubters point out that other countries, like Canada, have seen similar declines, even though their drinking-age is 18. They also argue that barring young people from drinking does not stop them from consuming alcohol: it just makes them drink more quickly. John McCardell, former president of Middlebury College in Vermont, is part of the Amethyst Initiative, a group of educators who are pushing for 18-year-olds to be allowed to drink. "Those who have graduated from high school, have a clean record and completed an alcohol-education programme should qualify for a drinking licence," he says, "in the same way that people who go to driving school receive a licence to operate a vehicle." This is not the first time that Americans have desired a change in alcohol policy during a period of economic distress. Franklin Roosevelt lifted prohibition in 1933 amid the trouble of a depression.
单选题
All the U.S. state governments used to follow the "21 law" because _____.