For any president, you can write down a list of bad things that happened, or policy initiatives that did not turn out well. But it's hard to know if that is due to the sitting president being unusually bad, or just the circumstances being unusually bad. E.g. Obamacare has various flaws compared to an ideal health care system, and it would have been better if the websites had worked on schedule. But on the other hand Obama actually managed to pass some kind of universal health care (something that illustrious names like Clinton and Ted Kennedy had tried and failed). So does that mean that Obama is a bad health-care reformer, or an exceptionally good one? It's hard to know, because we can't contrafactually plonk down Abraham Lincoln in the 2008 White House chair and see how he will perform.