Americans are very generous to people with disabilities. Since passage of the Americans With Disabilities Act in 1990, millions of public and private dollars have been spent on curb cuts, bus lifts and special elevators. The idea has been to enable people with disabilities to live and work with the same ease as others, as they make their way forward in life. I feel sure the large majority of Americans are pleased that we are doing this. But there is another federal program for people with disabilities that has had an unhappier effect. This is the disability insurance (DI) program,...