Obama was a great campaigner, but he's also more easily likable and a much, MUCH better speaker. Hillary might be likable in real life if you got to know her, but she didn't project it to people at home who watched her on TV the same way Obama could.
Even now Obama was drawing big crowds when he went out and campaigned for Hillary and his speeches were still great and moving. Hillary on the other hand just isn't that captivating when she speaks. Seriously if Hillary could captivate people like Michelle has been doing when she was speaking to the crowds for Hillary, I think people would be alot more forgiving of her faults the same way so many people have been so forgiving of Trump's many, MANY faults.