Costly Promises LOCKPORT, N.Y. — For two and a half years, Michael Tucker was mayor of this small city by day and an autoworker by night. Then in May, he became one of the nearly 50,000 workers at General Motors or its former Delphi parts division to take buyouts, lured by the $33,000-a-year pension his company offered. That pension, and a smaller one he expects to collect from the state after his years as mayor, makes him a little unusual in a nation where more and more workers are not covered by such plans. But now, as mayor of Lockport,...