The president’s economic advisers, led by Treasury Secretary Timothy Geithner and National Economic Council Director Gene Sperling, have argued behind the scenes for curtailing benefits, according to Democratic sources who have discussed Social Security reform with senior administration officials.

“This is extraordinarily upsetting to me,” Sanders said of the willingness of some senior White House officials to accept cuts in benefits. “It’s part of the president’s, or at least some of his people’s shift — significant shift to the right here.”