Gov. Charlie Crist says in a new television ad that he’s against raising the retirement age as an option for keeping Social Security solvent, and criticizes Republican U.S. Senate rival Marco Rubio for proposing to raise the retirement age and reduce benefits.

“Work longer, get by on less. That’s the Marco Rubio retirement plan,” the ad says.

In a retiree haven like Florida, it’s no surprise the program has been largely an untouchable sacred cow in the state’s politics. There are currently more than 2.5 million retirees in Florida on Social Security and reductions in benefits or changes in eligibility elicit strong reactions here.

But with nearly 80 million baby boomers hitting retirement age and a smaller pool of people to pay into the system, current estimates have the Social Security surplus running out in 2037, a deadline spurring one of the most fractious debates of this midterm congressional election – what to do about it.

Rubio has suggested that Congress should address the problem by changing the retirement age for future retirees and recalculating the inflation index. Rubio has said repeatedly he wants the benefits and requirements to remain the same for current beneficiaries already drawing Social Security, but that future beneficiaries may have to accept changes.

“Younger workers like myself … we’re going to have to accept that there’s going to be some changes,” Rubio said recently on CBS’ Face the Nation. “Perhaps they’re going to have to change the way the benefit is indexed. Perhaps we’re going to have to continue to allow the retirement age to fluctuate as it has been doing since the early 1980s. But again, that’s for younger workers like myself that have 20 or 30 years to prepare for this.”

Rubio pointed out in the same interview that his mother, who is 80, is one of those current beneficiaries who rely on Social Security as their only source of income, and emphasized that people currently drawing checks shouldn’t see any change. Nationally, about 50 million people draw Social Security checks.

Crist has said he would keep benefits and the retirement age as is, and tried to highlight that as a contrast with Rubio’s proposal to change it. But the governor, who left the Republican Party in April, has made only one suggestion about what to do about the looming shortfall. Crist has suggested that if more immigrants already in the country illegally were to be granted a path to citizenship, they could help prop up Social Security.

“Studies show that 11 to 14 million people are in the country as noncitizens, and if we are willing to have a thoughtful, reasonable pathway to citizenship -- earning citizenship -- then those 11 to 14 million people can become productive, participating members of the American economy, paying the payroll taxes, helping Social Security going forward, and making America stronger financially," Crist told The Huffington Post last week.

Most experts and federal officials, however, say generally that Crist’s idea won’t work the way he says. That’s because Social Security actuaries say about two-thirds of undocumented workers are already paying into the system through their jobs, though most don’t get any benefits. In fact, advocates for immigrants recently trumpeted a report from the system’s chief actuary that said undocumented immigrants already prop up the Social Security system -- to the tune of about $12 billion in 2007.

The Democrat in the U.S. Senate race, U.S. Rep. Kendrick Meek, says in campaign literature that he is “a firm opponent of gambling with seniors’ benefits by privatizing the program or raising the retirement age.”