Social Security currently keeps 20 million Americans out of poverty. It’s the principle source of income for roughly half of all seniors. Their dependence on the program increases with age. About two-thirds of those 80 and older get more than half their income from Social Security. With a looming retirement crisis and millions of Americans facing a sharp decline in living standards at the end of their working lives, Social Security may be their only nest egg.

Some have made a case that the proper approach to Social Security is to expand it by increasing benefits. This would bring more people into its embrace, including college-age survivors of deceased workers. Sen. Elizabeth Warren (D-Mass.) has now made that point. As the Democratic Party’s most visible and influential liberal, she is spearheading the debate.

Warren joins Sens. Tom Harkin (D-Iowa), Bernie Sanders (I-Vt.) and Sherrod Brown (D-Ohio) as a leading defender of Social Security in Congress. Her emergence in the vanguard of the movement to expand Social Security establishes a policy position for the 2016 Democratic platform.

We need to have a different conversation,” Warren said. Last week, she took aim at proposals to base the program’s inflation adjustments on a new index called the Chained Consumer Price Index, which measures the actual cost of living for the elderly and tends to rise slower than the basic consumer price index used today. “It’s just a fancy way of saying ‘cut benefits,’” she said. 

Warren said Social Security is all that stands between 20 million Americans and poverty. She called for “modest adjustments,” such as taxing the wealthy and immigration reform.