NONE of them are great, even Hillary isn't. I don't care about Trump or Biden or Clinton, because, in my opinion, Barrack Obama was the best US President I've ever seen. He did try his best for the good of his people, he respected them. I've heard some people say that he did nothing except making the immigrants think that the role of the common people of America is a joke (which isn't true). My answer is: ''If he did so, then just forget about the immigrants. Let America stand up on its own. I believe the country is strong enough for that''.
DISCLAIMER: *Just my opinion. I don't want to get involved in political arguements, because different people may have different opinions. And I don't live in the US, so I've no clear idea about its internal situation.*