MANCHESTER, N.H. – Drawing another distinction with Democratic front-runner Hillary Clinton on Friday, Sen. Bernie Sanders told seniors here that he supports expanding Social Security benefits and raising the payroll tax cap on the program – two days after the former secretary of state declined to endorse a similar proposal in the first-in-the-nation primary state.

“I think Secretary Clinton and I have a difference of opinion on this,” Sanders said at a local senior center. “I think she and I have a strong disagreement on this.”

“I do not believe in raising the retirement age for people who have been on Social Security,” Sanders continued. “I am categorically against what many of my Republican friends are talking about, cutting Social Security benefits.”

He went on to say he that favors raising or eliminating entirely the cap on taxable income for social security, so that more money would flow into the system to expanded benefits. Currently, only the first $118,500 of income is covered subject to payroll taxes, which funds Social Security. “We need not only to extend social security benefits, we need to expand them,” he said.

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Clinton on Wednesday raised some eyebrows on the left during her own appearance in the Granite State when she did not categorically rule out Social Security benefit cuts or raising the retirement age. And she declined to endorse an across-the-board expansion of benefits, as favored by many progressives.

“If there were a way to [raise the retirement age] that would not penalize or punish laborers and factory workers and long distance truck drivers and people who really are ready for retirement at a much earlier age, I would consider it. But I have yet to find any recommendation that I would think would be suitable,” she said.

Clinton added that she would “look at raising the [payroll tax] cap,” but did not endorse it, saying she did not want to increase the tax burden on middle class families.

That led some progressive activists to wonder about Clinton’s plans for Social Security.

“We know exactly where Senator Sanders stands on Social Security, he has been a champion in the fight to protect and expand Social Security for years … Martin O’Malley has released a detailed plan on how he would expand Social Security,” said Alex Lawson, the executive director of Social Security Works, which works to defend the program. “We have a sense of where Secretary Clinton is based on her public statements, but without a specific plan her comments leave a possibility that she would be open to cuts for some people.”

Raising the cap, as Sanders has proposed, would mean increasing payroll taxes on families making more $118,000. That’s why some Democrats who support raising the cap have proposed raising it only on the super wealthy. Meanwhile, the cap was an intentional mechanism put in place to make Social Security less redistributionary so the program would not feel like welfare to wealthier Americans.

Expanding Social Security benefits has become a top policy goal among many liberal policy wonks and activists, who seniors need more money, that the idea is extremely popular, and that it would help Democrats fend off attacks on the Social Security in general.

Progressive groups and lawmakers fought an intense battle with the Obama White House in 2012 and 2013 after they proposed trimming benefits for some seniors as part of a “grand bargain” with Republicans.

“Democratic primary voters deserve to know exactly where Secretary Clinton stands on Social Security,” said Murshed Zaheed, the acting political director of the progressive online organizing group CREDO. “Sec. Clinton needs to draw a line in the sand and make it clear that she will veto any bill that cuts Social Security benefits or raises the retirement age.”

Seitz-Wald reported from Washington.