* Jim Hightower (Commentary, Sept. 5) is the first commentator I have read that seems to understand the seriousness of the concentration of wealth on our economy. Simply put, the problem is this: Money that goes to the rich is money that does not go to the workers. The workers are the consumers and after 12 years of making the rich richer and the workers poorer, the poor no longer have the money to buy what is produced. Supply-side economics has had its chance and failed. Now demand-side economics must be given a chance. That means a massive shift of wealth from the rich to the poor. President Clinton made a start with his proposed income tax adjustment, but I am afraid it is tragically too little.