Washington ? The White House and Democrats are laboring to attract skeptical seniors to their drive to reshape the nation’s health care system, leading some to press the behemoth but reluctant AARP to be more aggressive about backing them.

Polls show people age 65 and up — the only age group that preferred Republican presidential candidate John McCain last November — have also had the most negative views about President Barack Obama’s attempt to overhaul health care. Among that age group, six in 10 disapprove of the job Obama is doing on health care and about the same number oppose the plans being considered in Congress, according to an Associated Press-GfK poll earlier this month.

To help combat that, some Democrats are prodding AARP, formerly known as the American Association of Retired Persons, to explicitly endorse their plans. While actively supporting the overall health care effort and many of Democrats’ specific proposals in an expensive public relations effort, AARP officials are resisting taking partisan sides in the sharply political debate, at least for now.

“Our focus is on issues,” said Nancy Leamond, who oversees AARP’s health care lobbying. “It’s not on any particular political party, and it’s not on any particular member (of Congress) and his or her proposal.”

In the administration’s latest attempt to win over seniors nervous about cuts in Medicare, Vice President Joe Biden visited a Maryland retirement community on Wednesday and told them, “Nobody is going to mess with your benefits. Nobody. All we do is make it better for people on Medicare.”

AARP is a tempting target as Democrats search for allies with influence among the nation’s elderly. The organization has 40 million members age 50 and up with whom it has unparalleled credibility — many of whom consistently vote.

“Even if they didn’t take a side, just to provide factual information to their membership I think would be a tremendous help,” Rep. Raul Grijalva, D-Ariz., a leader of the liberal Progressive Caucus, said of AARP. “Because they’re seen as unbiased and they’re seen as advocates for older Americans.”

That message was also delivered to AARP last Thursday, when House Democratic leaders brought Leamond and A. Barry Rand, AARP’s CEO, to a meeting on health care with rank-and-file Democrats, participants said. In addition, House Majority Leader Steny Hoyer, D-Md., said he has met with AARP executives “and certainly have urged them to weigh in as heavily as they can.”

The sheer size that gives AARP clout also often ties its hands when it comes to deciding whether to back specific bills in Congress, a frequent source of frustration for both political parties in Washington. The organization says its membership is divided about evenly among Democrats, Republicans and independents — meaning any endorsement of a partisan position is likely to anger many AARP members.

AARP officials say 60,000 of its members quit between early July and mid-August citing its support for a health overhaul, though it picked up 400,000 new members during the same period and renewed 1.4 million other memberships. They did not respond when asked to provide more current figures.

Democrats are not solely looking to AARP for help in winning over seniors. The labor-backed Alliance for Retired Americans, along with the American Federation of State, County and Municipal Employees, have produced a video featuring Lynda Bird Johnson Robb discussing the struggles her father, President Lyndon Johnson, faced in the 1960s during his battle to create Medicare. The National Committee to Preserve Social Security and Medicare, another advocacy group, is mailing a brochure that generally supports the health overhaul to its 800,000 members.

None, though, compare to AARP.