I keep hearing this from the Democrats, but I don't believe it. It sounds like one of those 'facts' that everyone uses but has never been independently verified. Like that nonexistent "Lovenstein Institute" report about Bush's low IQ that was finally debunked.
It's probably true because it's a relatively small number. You notice she doesn't mention the real reason for the shortfall, or where the expenditures really go: K-8 schools and medical care.
At $10/hr (which would be a high wage), the great unmentionables would avg $20k/year. Since they seem to have around 4 kids apiece, and at an avg cost of $6k/year to edumicate them, we're already upside down to the tune of $4k/family if the entire $20k was paid-in as taxes. In reality, of course, they pay little if no tax, and receive a hugely disporportionate share of benefits.