Social Security has always seemed like a future problem, with experts long predicting a benefits squeeze in the decades ahead. But the coronavirus has put tens of millions of Americans out of work, and economists are predicting that the recovery will take years.

That means the future is now.

If nothing is done to shore up the program, all benefit checks would need to be cut by roughly one-quarter in perhaps 11 years — or, if the recession is protracted and severe, maybe even sooner.

"We thought we had more than a decade, and now it could be less than a decade," said Kathleen Romig, a senior policy analyst at the Center on Budget and Policy Priorities. "That makes a big difference both psychologically and in policy terms."

The pandemic has hastened the cash crunch's arrival by wiping out jobs and the payroll taxes — Social Security's dedicated source of revenue — that they provide. Fewer people are paying into the retirement trust fund, and the longer they're out of work, the deeper the problem becomes. (Even more pressing may be a fix for Social Security's disability program, which has a trust fund of its own. A report issued by the Congressional Budget Office last month projects that fund could be exhausted in 2026.)

Despite such grim projections, Social Security hasn't received a lot of attention during the presidential campaign, given everything else going on. But whoever wins next week will have little choice but to stretch out his hand toward the third rail of politics. And both candidates have offered ideas that could significantly shift how Social Security works.

President Donald Trump hasn't released a proposal, but he has said he wants to eliminate the payroll tax as an expansion of the temporary holiday enacted by executive action over the summer. (Few companies have stopped collecting the tax, which would have to be repaid in 2021.)

"At the end of the year, on the assumption that I win, I'm going to terminate the payroll tax," he said in August. Instead, he said, he would pay for the program through the general budget, which could count on "tremendous growth."

Trump has stated this on more than one occasion, but Sarah Matthews, deputy White House press secretary, said the president meant only that he wants to forgive the taxes deferred under his order.

"President Trump will always protect Social Security, as he has stated numerous times," she said.

Policy experts are highly skeptical that the payroll tax could be eliminated; it would require congressional action and be politically difficult. But if it happened, Social Security would have to compete for funding in a way it hasn't before.

"We have a very crowded budget as it is," said Shai Akabas, economic policy director at the Bipartisan Policy Center. "And having Social Security in the mix with everything else puts the program at risk in the future."

Joe Biden, the Democratic nominee, has released a proposal that's more moderate than many offered by his party's progressive wing. But it would nonetheless make fundamental changes.

Biden proposes an expansion of the payroll tax, but only on the highest earning Americans. Currently, the payroll tax — 12.4%, split between employees and employers — applies to the first $137,700 of a worker's earnings. Under Biden's plan, high earners would also have the tax assessed on their earnings above $400,000. (Because the $137,700 threshold rises over time, eventually all income up to $400,000 would be subject to the tax — in about 30 years, the Urban Institute estimated.)

For decades, the amount a worker pays into the system has factored into how much they ultimately receive in benefits. But Biden has suggested that higher earners might not get anything in return for the added tax they pay, a change that would break a link that has been in place since the program began. The issue is still being studied, however, and no decision has been reached.

Even with the tax on high earners, Biden's proposal would buy the program only an additional five years of solvency, according to the Urban Institute analysis, although it would soften the benefit cuts that would be necessary if further changes aren't made.

Biden's policy advisers, however, said the proposal is something of an opening bid.

"The vice president's financing proposal shows how he would protect and increase benefits for all Social Security recipients while making a down-payment on long-term solvency," said Gene Sperling, an outside adviser to Biden and a former national economic adviser to Presidents Bill Clinton and Barack Obama.

The cost of inaction is serious, Akabas said, because as insolvency creeps closer, the changes necessary will become increasingly painful — tax increases will need to be greater, any cuts more severe.

"The longer we wait to fix the problem," he said, "the fewer people who can play a role in the solution."

About half the population 65 and older live in households that receive at least half of their income from Social Security, according to a 2017 study published in the Social Security Bulletin. Roughly 25% of elderly households rely on Social Security for at least 90% of their income.