Purity of sport ended when athletes became professional. When athletes can only compete with the help of dieticians, sports psychologists, professional stretching coaches, and computerized stroke analysis, what's the point of holding back on drugs? Is there really a difference between shooting up with steroids and shooting up with a customized diet goo made with the precisely the right balance of pre-digested amino acids? Will Saletan already made the argument that lasik for pitchers is essentially the same as doping. Why are drugs used to aid recovery any different from a customized two hour massage after every work out to remove lactic acid buildup from muscles? And frankly, who the heck cares if a bunch of guys (and women) with bodies that are essentially freaks of nature want to make themselves more freakish? If the only way to become a professional athlete is to start training at birth and have every physical, psychological, dietary, and environmental aspect of your life controlled by someone else, there's just no connection between the weekend softball game and Sunday afternoon with the Yankees.
As to what would happen: Focus on the Family would boycott baseball. Evangelicals would leave sports stadiums in droves. The law and order crowd would have a conniption fit. Hmmmm.... can we time this so it happens just before the '08 presidential election?

When athletes dope under medical supervision, we learn about the long-term effects of various performance-enhancing substances. That provides a benefit to the rest of us when so-called dope is used to treat medical conditions, such as aging or injury. Experiments with anabolic steroids have already shown them to have anti-geriatric effects. Putting them in the same class as heroin or ice means that people who could benefit from them lose.