While the benefits cut would hurt across the board, it will hurt women more as a group because they've worked for less income, are more likely to have gaps in work history and part-time work, and thus get less when it comes time to collect Social Security. The average annual benefit for a man is $17,000 and for a woman it's $13,000.

That generous (cough) $13,000 is more likely to be a woman's primary source of retirement income. "In 2010, 38 percent of older women age 80+ that lived in a family receiving Social Security relied on it for 90 percent or more of their income, compared to 28 percent of older men age 80+."

The cuts will be deeper for women because they will live longer and make up a greater share of the very old population. If you use the Simpson-Bowles formula for the chained CPI, by 86 the typical single elderly woman would have lost more than $8,400 in cumulative benefits since retirement compared to the current structure. By age 95, it would be $12,000. That's a hell of a lot of groceries.

The 38 percent of older women saved from poverty in 2011 (and 32 percent of men) would slide right back down into dangerous poverty territory. For a typical 80 year old single woman, her monthly benefits would be reduced by $56 (again, using the Simpson-Bowles formula). That's a very large chunk of a grocery budget. Or rent. Or prescriptions or medical supplies not covered by Medicare.

Speaking of prescriptions and other medical costs, that's what seniors spend a lot of their money on. Those are fixed costs that tend to rise faster than the general rate of inflation and are difficult to substitute. Which is the whole fallacy behind the chained CPI. It relies on the substitution effect. You can't afford to by beef anymore? You buy chicken instead. You can't make that choice with a your eye glasses, or you dental care. You go without, or you substitute your chicken with cat food. And yes, women are hit harder here. On average, an elderly woman spends nearly 19 percent of her income on medical needs; a man, a little over 14 percent.

AARP is just goading Alan Simpson into saying something offensive and ridiculous again, this time by point out the "terrible, horrible, no good, very bad impact on women" within the chained CPI, a new way of measuring the cost of living that would mean immediate benefits cuts to seniors and disabled veterans. But the biggest and most vulnerable group, as AARP notes, is women.

The White House has insisted that the "most vulnerable" will be shielded from the cuts. Will that be the vast majority of women, 75 percent of whom rely on Social Security for at least half of their income? For the relatively small deficit savings that would be achieved if all the truly vulnerable people were exempted from this cut, it can't possibly be worth the pain.

The only thing passing the chained CPI in a grand bargain would do would be to give the Republicans the trophy of getting a Democratic president and senate to cut Social Security. A trophy that they would promptly start beating Democrats over the head with in elections from now until forever. It's just not worth the pain.

Send an email to the White House telling President Obama to immediately stop proposing any cuts to Social Security.