I don't know the yardstick you are using to measure the performance of past Presidents of the United States of America that made you conclude that Barak Obama's term in office was not fairly good. Regardless of how productive a leader is, he would have area of strength and weakness. Such leader's performance would be rated excellent in some sectors or sections, while in other areas he might been seen as a failure. Abraham Lincoln that is mostly regarded as the greatest president of the US is also disliked in some area.
I don't think Dr. Claudine Gay needs to go the extra mile or do the extraordinary just to prove to the world that a black woman can make a difference. All she needs to do, is to put in her best and ensures that the goals and aspiration of Harvard is achieved during her tenure. After all we have had 29 past Presidents and I am sure that only few made the so-called difference. But having a a person of color leading Harvard in the institution's four hundred years of existence is a good news. It would no doubt give the people of color a sense of belonging.
Thanks for your comment. My saying "Obama was fairly good" is not based on his performance compared to other Presidents' but only to my high expectation back then. Whether my opinion is reasonable or not does not matter over here because I just wanted to use Obama or even Harvard's new President to bring up this topic. Maybe I'd better to put it this way: a sense of meaning/belonging is sometimes important than a sense of being. Whether Obama or Dr. Claudine Gay was/will be great seems not that important.