• Social Security beneficiaries may face an across-the-board benefit cut in the next decade if Congress does not take action sooner.
• While Congress seems to be at a standstill, some say a bipartisan commission is the answer.
• Here's why the idea has drawn both fierce opposition and fierce support.

A protester interrupted a January congressional committee hearing to consider a bill that would create a bipartisan commission to address Social Security. "A vote for a commission is a vote to cut Social Security," the man shouted before he was escorted off the floor.

While there was a protest of one that day, there has been a chorus of opposition to the idea of creating a commission, as well as strong support — from experts and politicians on both the left and the right.

The combined trust funds Social Security relies on to pay benefits are now projected to be depleted in 2035. On that date, the program will be able to pay just 83% of benefits.

But another date — the depletion of the trust fund specifically devoted to retirement benefits — is approaching sooner. Less than a decade from now, in 2033, Social Security may pay just 79% of those benefits.

Most Americans, 89%, think Congress should act immediately to make sure full benefits are available to both current and future beneficiaries, a 2023 AARP poll found. And 90% said Republicans and Democrats should work together to find a solution.

"We all as Americans want to get ourselves into a room, face the facts, make the hard choices and then communicate with the public about how we save this program," said Rep. Scott Peters, D-Calif., in an interview with CNBC.

Peters is pushing for the Fiscal Commission Act alongside Rep. Bill Huizenga, R-Mich., and Sens. Joe Manchin, I-W.Va., and Mitt Romney, R-Utah.

The bill would create a commission to provide policy recommendations to address the federal government's long-term fiscal issues, and those proposals could get expedited consideration from Congress. The commission would also be responsible for a public awareness campaign to educate Americans about the country's current fiscal situation.

Another Democratic leader — Rep. John Larson of Connecticut — has vehemently opposed the proposal, due to the closed-door nature of the negotiations and the priority consideration any ensuing recommendations would receive.

"It's probably one of the most undemocratic things that a Congress has ever put forward," Larson said.

Instead, Larson is championing his own bill, Social Security 2100, to improve the program's solvency and expand benefits through tax increases targeted at the wealthy.

Social Security advocacy groups have also staunchly opposed efforts to create a commission.

"This is a thinly veiled effort to avoid political accountability," Nancy Altman, president of Social Security Works, recently testified in an April congressional committee hearing.

How the last major reforms, in 1983, came together

The last major Social Security reforms, which were enacted in 1983, were preceded by a commission.

The National Commission on Social Security Reform, formed in 1981, is often called the Greenspan Commission, after its chairman, economist Alan Greenspan, who more famously served as chairman of the Federal Reserve.

"Most commissions, of course, don't do anything," Greenspan wrote in his 2007 memoir, "The Age of Turbulence." "But [White House chief of staff] Jim Baker, the architect of this one, believed passionately the government could be made to work."

The bipartisan commission included 15 members chosen either by the White House, the Senate majority leader or the Speaker of the House. Every commissioner was an "all-star in his or her field," according to Greenspan.

"I ran the commission in the spirit that Jim Baker had envisioned, aiming for an effective bipartisan compromise," Greenspan wrote.

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The group had a tall task — to come up with recommendations to solve the financing crisis the program faced at the time.

The Social Security amendments President Ronald Reagan signed into law in 1983 "involved pain for everyone," Greenspan wrote.

The changes involved taxes on Social Security benefits, increases to payroll tax rates, a future increase to the retirement age and a near-term postponement of cost-of-living adjustments.

At the time, the changes were projected to enable Social Security to pay full benefits through 2057.

Today, the projected date is 2035, with rising income inequality contributing to the depletion dates being pushed up, according to the Economic Policy Institute and other experts. Social Security payroll taxes are capped at $168,600 in earnings. As wage growth for high earners outpaces average wage growth, more income falls above the threshold where it is not subject to Social Security payroll taxes, the EPI says.

'Not an example of a successful bipartisan commission'

The 1983 legislation is often touted as a grand bipartisan bargain between Reagan, a Republican, and House Speaker Tip O'Neill, a Democratic congressman from Massachusetts.

Yet some Greenspan Commission participants have opposed using it as a future model for reform.

One prominent critic was Robert M. Ball, who served as the commissioner for Social Security under three presidents and who represented O'Neill on the Greenspan Commission.

"Nothing, however, should obscure the fact that the National Commission on Social Security Reform was not an example of a successful bipartisan commission," Ball wrote in a portion of the memoir he was working on when he died in 2008. The memoir, "The Greenspan Commission: What Really Happened," was published in 2010.

"The commission itself stalled — essentially deadlocked despite continuing to talk — after reaching agreement on the size of the problem that needed to be addressed," Ball wrote. "As a commission, that was as far as it got."

More recently, in November, five staff members who worked on the commission — including Altman of Social Security Works, who served as Greenspan's executive assistant — issued a statement to urge policymakers not to use it as a model to fast-track changes including benefit cuts.

"In the end, they left a big hunk of the problem to be solved by the Congress, which solved it," Bruce D. Schobel, who served as a staff actuary on the commission and signed the statement, said in an interview with CNBC.

The increase to the retirement age that is still getting phased in today resulted from House amendment, rather than from a commission recommendation, the staff members said in their statement.

Since 1983, there have been similar efforts to create a commission to consider Social Security that have failed, the staff members noted.

"Congress should address Social Security in the sunshine through regular order, as it always has," the staff members wrote.

Lawmakers divided on best path forward

Today, lawmakers are divided on the best path forward to address Social Security.

Larson, the Democratic congressman representing Connecticut, hopes to advance his bill.

The Social Security 2100 proposal currently has almost 200 Democratic House co-sponsors. The bill would provide a host of benefit increases — including a 2% across-the-board benefit boost — which would be paid for by adding Social Security payroll and investment taxes for individuals with earnings above $400,000.

A similar proposal put forward by Sens. Elizabeth Warren, D-Mass., and Bernie Sanders, I-Vt., would apply tax increases for earnings over $250,000.

If the Social Security 2100 bill makes it to the floor, it may pass "overwhelmingly" on a bipartisan basis, Larson predicts.

"Congress needs to vote," Larson said.

But Peters — the Democratic congressman representing California — said he believes a bipartisan commission is the answer after Social Security 2100 failed to move forward even under Democratic control of the White House and Congress.

"I think the other efforts are honest efforts and they're just not going to pass," Peters said.

He said that by waiting until the last minute ahead of the projected depletion date, lawmakers who are facing a 21% across-the-board benefit cut may instead negotiate that down to 15%.

"If I wanted to cut Social Security, [if] that was my goal, what I would do is do nothing," Peters said. "My goal is not to have any cuts."

The 1983 reform efforts are a lesson to not wait until the last minute, he said.

"When you say, 'Don't touch Social Security' in the situation it's in, it's like telling the doctor not to treat the cancer patient in the hospital," Peters said. "It's just dumb."

The Fiscal Commission Act has drawn criticism from both Social Security advocates on the left and notable figures on the right, including former House Speaker Newt Gingrich and Grover Norquist, president of Americans for Tax Reform.

Peters takes opposition as a sign they're in the "right spot" for bipartisanship.

"I don't understand why anyone would do this job if they don't want to fix these big problems," Peters said. "And that's why we're sent here explicitly."

Experts including Altman have said the future of Social Security is on the ballot this November.

The AARP is posing one question — What is your position on Social Security? — to all candidates for federal office this year.