Lobbying organization AARP’s support for changes to the nation’s health care system has cost the group thousands of members, and is now implementing a campaign to persuade seniors that it is an impartial advocate for the health care consumer.

“To be clear: AARP has not endorsed any comprehensive health care reform bill — but we are fighting for a solution that improves health care for our members,” said CEO Barry Rand and president Jennie Chin Hansen.

Many of the approximately 60,000 AARP members to resign their membership since July fear that changes to the health care system would result in cuts to Medicare. AARP has not endorsed any specific plan, but its support for improvements in health care gave many members the impression that it supports President Obama’s plan. The large number of protest resignations startled leaders of this powerful organization, which claims 40 million members. Although the group lost some members over the health care debate, it reports gaining 400,000 new members over the same period.

“The last thing I want is for members to feel we’re not representing them,” said Lori Parham, AARP’s Florida director.

The new publicity effort has included direct-mail communications, a fall newsletter debunking health care myths, town-hall forums to discuss the changes being considered and national television and Web ads about the topic. Through this information-dissemination campaign, AARP hopes to hang on to members trying to decide whether to quit the group, such as Ted Campbell, who heads up a Republican group at a retirement community in Springfield, Va. Campbell, 80, complained that AARP did not appear to be staying politically neutral in the health care debate.

Campbell’s main concern is “rationing of treatments. It sounds to me like, based on age, they’re going to determine whether you get treatment or not. I don’t think that’s the way to control health care costs.”

AARP’s legislative director, David Certner, notes that seniors’ current concerns regarding care rationing and benefit cuts seem to differ sharply from the concerns they have voiced over the past several years.

It was those earlier concerns, including the high cost of health care, the difficulty getting insurance for those between 50 and 64 years old who don’t yet qualify for Medicare and the high cost of prescription drugs, which led the group to support reform of the system.