Medicaid has long conjured up images of inner-city clinics jammed with poor families. Its far less-visible role is as the only safety net for millions of middle-class people whose needs for long-term care, at home or in a nursing home, outlast their resources.

With baby boomers and their parents living longer than ever, few families can count on their own money to go the distance. So while Medicare has drawn more attention in the election campaign, seniors and their families may have even more at stake in the future of Medicaid changes — those proposed, and others already under way.

Though former President Bill Clinton overstated in his convention speech on Wednesday how much Medicaid spends on the elderly in nursing homes — they account for well under a third, not nearly two-thirds, of spending — Medicaid spends more than five times as much on each senior in long-term care as it does on each poor child, and even more per person on the disabled in long-term care.

Seniors like Rena Lull, 92, who spent the last of her life savings on $250-a-day nursing home care near Cooperstown, N.Y., last year, will face uncharted territory if Republicans carry out their plan to replace Medicaid with block grants that cut spending by a third over a decade.