In Doug Henwood's latest Radio Commentary, he states:

On that point, a reminder of how little it would take to end poverty
in the USA. The so-called poverty gap, the amount of money necessary to
bring everyone whose household income is below the offical poverty line
up to that line, was about $138 billion in 2008, less than 1% of GDP.
Or, to put it more bluntly, about what the Pentagon spends in two
months. Or 3% of the total income of the richest fifth of American
households. Or roughly what we spent bailing out AIG. But Wall Street
and the war machine really need the money, you see.

Of course the official poverty level is far too low, as many, including Doug, have pointed out, but it would be a start.