This is going to be a little brutally honest. Some people are poor because of the choices they make as opposed to situations that they have no control of.
There are only 0.4 workers per household in the poorest income quintile as opposed to 2.1 workers per household in the richest income quintile. 
Also, nearly 20% of poor households are single women with children as opposed to 3.6% for rich households. (This may not be the woman's fault if the father of their children walks out on her). 
It's also worth noting that only 3% of full time workers live below the poverty line according to US census data. This is in stark contrast to 33% of the unemployed living below the poverty line. 
Similarly, the Heritage Foundation notes:
"In good economic times or bad, the typical poor family with children is supported by only 800 hours of work during a year: That amounts to 16 hours of work per week. If work in each family were raised to 2,000 hours per year-the equivalent of one adult working 40 hours per week throughout the year- nearly 75 percent of poor children would be lifted out of official poverty.
Father absence is another major cause of child poverty. Nearly two-thirds of poor children reside in single-parent homes; each year, an additional 1.5 million children are born out of wedlock. If poor mothers married the fathers of their children, almost three-quarters would immediately be lifted out of poverty." 
If everyone emulated the actions of the very rich (get married, have a full time job, etc), poverty would decrease dramatically.
(below graphs are taken from citation #3 (top) and citation #1 (bottom))