An article on efforts to persuade President Obama to drop his proposal for adopting the chained CPI for indexing Social Security benefits told readers:
"liberal policy experts estimate [the change] could cost seniors thousands of dollars in benefits over their lifetimes."
This is not something that just liberal policy experts have estimated, it is a fact. The proposal would reduce annual benefits after retirement by roughly 0.25 percentage points a year compared with the current index. That would lead to a reduction in benefits of several thousand dollars for a worker who lives to collect benefits for twenty or thirty years. This is how the change would save the government money.
Note: I wrongly attributed this to Politico in the original post. Thanks to Robert Salzberg for catching the mistake.