If you define poverty not by an absolute standard of living but the poverty trap (the range where the rest of society trivially exploits you, intentionally or not, and you cannot advance as they do), does it triple?
The actual progress in standards of living in the USA from 1930 to 1980 is hard to overstate.
Society has implemented welfare safety nets and minimum wages for the express purpose of improving the lot of the poor, at a non-trivial cost to the rest (i.e. financial net-contributors) of society. The wages that the poor are able to command (above the proscribed price floor) are the result of market forces of supply and demand; the prevalence of unskilled labor results in low pay--not society or greedy business owners.
The fact that society doesn't do even more to put money in the pockets of the poor can't be 'exploitation', unless you're 'exploiting' a homeless man when you put a dollar in his cup, when you could've put two.
Unless you're talking about loansharks, pay-day-lenders, and that sort of thing, in which case you're right, screw those guys.
https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
More precisely the real value of median income tripled from the 1930s to the 1980s. Lower income brackets did likewise.
So it is historically incorrect to hear FDR say "decent living" and map it onto current notions of a decent living. Separately, we have many decades of experience with the program that FDR didn't, and therefore our opinions today can be better informed than his way. Therefore there is no particular reason that we today should feel bound to agree with his original views.