AFTER many years of controversy, day-care legislation in Washington is dead, at least for now. Congressional support has evaporated because the new forces needed to offer political aid and fresh arguments have not emerged, leaving the debate stalemated. But perhaps the principal reason for the deadlock is that the issue has been cast in the wrong terms, making any consensus impossible. Day care must be viewed as only part of the response to major changes in work and family life in this country, not as an autonomous issue. The questions these changes raise go well beyond day care, though to understand them we must first look at day care itself in some detail and explain what is wrong with the conventional debate.