In general Obama has been a good President; however at this moment there appear to be some significant failures. History may change perceptions, but it appears one of the main reasons his designated successor, Hillary, failed was that Obama failed to deal with income inequality.
Obama prevented the great recession from becoming a second great depression, but in doing so he rewarded the tycoons who caused the recession, rather than punishing them. Obama threw his support behind the super wealthy, who will no doubt reward him in retirement, as they did the Clintons. His decision has exacerbated income inequality to the point where it has become apparent to the population at large, which caused the backlash against him in the last election. It was certainly one of the most important factors in Trump’s victory.
The situation was not all Obama’s fault, since it started under Bush. The Republicans in Congress were strongly in favor of protecting the wealthy. The Democrats passed Dodd-Frank while they still could, but its limits were prospective, weak and did nothing to punish Wall Street for what it had done to create the 2008 mortgage crisis. Obama tried to protect the poor, especially Hispanics and blacks by placing the burden of recovering from the recession on the white middle class. I don’t think he targeted the middle class; it was just the course of least resistance to have them bail out both the lower classes and the super wealthy. But it highlighted the fact that Democrats didn’t really care about the middle class, which became increasing evident during Hillary’s campaign.
This is a bad part of Obama’s legacy that the Democrats will have to bear.