WASHINGTON (AP) — President Barack Obama’s offer to limit the growth of Social Security benefits would cost the average retiree less than $50 in the first year. But the cuts would grow over time, and that has advocates for seniors worried that Democrats in Congress will break their promise to shield the massive retirement and disability program from cuts in deficit reduction talks.

Both Senate Majority Leader Harry Reid, D-Nev., and House Minority Leader Nancy Pelosi, D-Calif., pledged not to touch Social Security as part of negotiations to avoid the year-end fiscal cliff. Reid, however, is backpedaling now that Obama and House Speaker John Boehner, R-Ohio, have agreed to a new measure of inflation that would reduce annual cost-of-living adjustments, or COLAs, for Social Security and other government programs.