WASHINGTON -- Hillary Clinton hasn't taken the most liberal posture on Social Security, and Martin O'Malley's campaign would like to make sure you know it.
"Democrats should have the confidence that our nominee will not cut Social Security, but right now that's just not the case," O'Malley campaign spokeswoman Haley Morris said in an email.
The comment comes as a Super PAC associated with Clinton's campaign put out an ad attacking Republican candidates as "wrong for seniors."
O'Malley, former governor of Maryland, and Sen. Bernie Sanders (I-Vt.), Clinton's chief rivals for the Democratic presidential nomination, have staked out clear positions on the popular retirement program, outlining specific tax and benefit changes. But Clinton's position has been slightly fuzzier.
At a debate last month, Clinton hesitated on the question of expanding benefits. She said that she wanted to "enhance" benefits for Social Security's poorest recipients. "We have a lot of women on Social Security, particularly widowed and single women who didn't make a lot of money during their careers, and they are impoverished, and they need more help from the Social Security system," Clinton said.
Clinton did not say whether her intention to enhance benefits for select groups also means she would oppose cuts in benefits to other Social Security beneficiaries.
"Sec. Clinton’s plan is still very general: while it does expand benefits for lower income individuals and especially women, what we really need from everyone is a clear line in the sand against cutting any Social Security benefits,” said Alex Lawson, executive director of Social Security Works, an umbrella campaign for many national groups advocating the expansion of Social Security benefits, in a statement.
"Governor O'Malley is the only candidate who set a goal to invest in retirement security for seniors," Morris said. "His plan will actually expand -- not enhance -- Social Security and has been praised by advocates and progressives as the boldest in the field."
Among other things, O'Malley's campaign has proposed increasing benefit amounts and improving the program's financing by adding the Social Security payroll tax to annual incomes above $250,000. Currently, just the first $118,000 in earnings are subject to a 12.4 percent payroll tax that is split evenly between workers and employers. Clinton's website suggests she would be open to higher taxes on higher earners.
Clinton's campaign has not responded to requests for additional Social Security policy details or reaction to O'Malley's comment.
Update: This story has been updated to include a statement from Social Security Works.