According to conservative estimates from the Pew Research Center, in 2011 there were 850,000 undocumented immigrants over the age of 55; 150,000 were over 65. That’s a relatively small portion of the 11 million undocumented immigrants in the U.S., but experts say the numbers of elderly without legal immigration papers are poised to grow rapidly as they follow the Baby Boom generation into retirement age. And they are likely to be among our society’s most impoverished people.

Because undocumented immigrants of all ages are twice as likely as the general population to live in poverty, elderly immigrants without papers are less likely to have amassed savings. To survive, many of these seniors are left with little choice but to keep working low-wage, often physically demanding jobs—street vending, cleaning houses or working as home caregivers—for the rest of their lives.

Lawmakers and others who oppose the passage of proposals that could help poor immigrants like Perez often argue that they are a drain on American taxpayers by using public services without paying their share. But Stephen Goss, the chief actuary for the Social Security Administration, says “in the case of Social Security trust funds, and analogously the Medicare trust funds, our estimates refute that idea.”