In a move that may turn out to be politically shrewd but will almost certainly turn out to be practically ineffective, 70 Democrats on Sunday delivered a letter to the White House urging President Obama, in the vaguest of possible language, to “expand Social Security benefits for millions of Americans.”

“As employers continue moving from a defined benefit model to a defined contribution model of retirement savings, it is critical that we fight to protect and expand Social Security –– the only guaranteed source of income in retirement,” the lawmakers wrote, on the eve of the once-in-a-decade White House Conference on Aging that convenes today.

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The word “expand” can mean different things, but it seems fairly clear that the members of Congress behind the letter, including presidential candidate Bernie Sanders (I-VT) and Rep. John Conyers (D-MI), are using the verb as a synonym for “increase.”

“Today, two-thirds of retirees depend on Social Security for the majority of their income,” they write. “More than half (53 percent) of today’s working Americans are not expected to have sufficient resources upon their retirement to maintain their standard of living.”

Why they didn’t specifically say that they want to require the government to pay more money to retirees every month isn’t clear. It might be that they don’t want to open themselves to attacks from Republicans over the fiscal responsibility of raising the cost of one of the nation’s largest entitlement programs. But that doesn’t make all that much sense, as one of the key points behind such a proposal, clearly, is to draw a sharp line between Democrats and Republicans.

There is a strong and very powerful narrative on the political right pushing the idea that Social Security is on the verge of bankruptcy and that the government will be unable to make the payments that generations of workers have been promised. A vocal segment of the left argues that the program can be brought right fiscally with some minor adjustments and that relatively minor tax increases can actually pay for substantially increased benefits.

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In the end, each side is working a strategy aimed at older voters, meaning those currently receiving Social Security and those expecting to receive it in the near future.

The Republican message is that Social Security is in mortal peril and might not be there in the future unless Washington takes serious and potentially painful steps to implement fiscal reform.

The Democratic message is that Social Security has fallen behind the times in terms of the benefits it offers. Retirees no longer have guaranteed pensions from their employers and the growing number of them who rely almost exclusively on Social Security for retirement income means that the benefit no longer provides the sort of dignity and comfort in retirement that it was intended to.

The Democrats who signed the letter to the president likely have few illusions about the likelihood of the current Congress – or any Congress in the foreseeable future – approving a substantial increase in the cost of one of the country’s major entitlement programs, particularly if it involves tax increases.

However, with attention focused on the Conference on Aging, voters -- and particularly older voters -- will be tuned in to Washington rhetoric more than usual. And the Democrats know what they want them to remember.

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