Advocates for the elderly are claiming a big victory because new budget rules make the $265 billion Social Security system virtually untouchable in future efforts to reduce the federal deficit.

The change has critics complaining that it makes little sense to exempt the government's single biggest domestic program from future attempts to narrow the budget shortfall.But it is a relief for more than 39 million elderly, handicapped and other Americans who get monthly checks from the program - and for politicians loath to cut the politically popular pension system.

"It's an important victory," said spokesman Bill Ritz of the National Committee to Preserve Social Security and Medicare, which lobbies for senior citizens.

In federal budget politics, removing one program from possible cuts simply means that other areas are exposed to potentially deeper reductions. As a result, some defenders of other programs are upset by the favorable treatment for Social Security.

"Whether they're elderly or children, if they're poor, they're poor," said Susan Rees, executive director of the Coalition on Human Needs, a Washington-based group that champions aid for low-income Americans of all ages. "Why should one have to sacrifice for the other?"

As part of their budget deal last month, the Bush administration and congressional leaders agreed to take Social Security out of the calculations used to determine the federal deficit.

Proponents said with the pension program running an annual surplus of tens of billions of dollars, the overall budget gap was being shrunk artificially under the old system.

That sounds like a dry accounting change, but it's not. What it really means is there is no longer any reason to look to Social Security for budget savings because cutting the program won't make the pool of red ink any smaller.