Take a close look at this graph showing the poverty rate over time:
There are several spikes in poverty and one significant dip. The first spike happened right around the early 80s, right after Ronald Reagan took office. The next spike happened right around the early 90s right after George Bush took office. The dip occurred around 1994, right after Bill Clinton took office. The next spike in poverty occurred right around 2000, right around when George W. Bush took office. In recent history, whenever a Republican took office and during their presidency, the poverty rate rose dramatically. Every Republican presidency resulted in a net gain in the poverty rate whereas the only Democratic presidency of significant length resulted in a net decrease in the poverty rate. We are only in the middle of the Obama presidency but we can start to see a small dip occurring.
Although there are a multitude of factors that impact poverty rates, presidents often set the economic mood. Think Reaganomics, the Bush tax cuts, Clinton raising taxes, etc. In any case, there is a significant problem that has been increasing ever since the early 80s that needs to be addressed.