MARINETTE, Wis. — In hundreds of meetings with millions of its members to promote a health care overhaul, AARP, the huge organization for older Americans, has often found itself forced to referee a battle between generations.

Lisa Lamkins, an AARP official in Wisconsin, explained the group’s health care stance to members on Tuesday in Marinette.

A blog from The New York Times that tracks the health care debate as it unfolds.

Its 40 million members are split about evenly between those who have access to Medicare, the federal government’s health program for the elderly, and those who are too young to be eligible for such benefits. The younger members, or those between the ages of 50 and 64, sometimes face terrible...