Honestly I think a lot of you are missing what a president needs to be and what qualities they need to show. It shouldn't matter as much if they have experience as long as they know what they're getting into with going into the role of presidency. It's not just another job that forces you to deal with people you may not like or understand, it's a spot of importance that says "You are the LEADER of these people."
I put an emphasis on leader because that's the big thing that the president should be. we shouldn't look for someone who tries to rally one type of people, but someone who can unify the nation and possibly the world with a showing of respect, honor, and dignity. The president should want the job to do things like that as well as make the world a better place for the next generation. Make earth healthy while still allowing people to enjoy what they have. Set the standard on what it means to be truly large and give the people the one thing they have not had in a long time, which is someone who is not just good, but great. A person who exudes greatness with every breath they take and commands respect with every word spoken. Do not confuse this for perfection, as no one person is perfect, but some can be perfect for a certain role. When you look back in history, a lot of past presidents have been good, but have any actually been great? Did they do great things for the country as a whole? For the people living in their country? For the world at large? These things do take time, and that's why one reason the legal age is 35. As we've seen however, a mature person age does not make. Maturity in itself is subjective though, as some people may say that playing video games is immature, even though video games are a great way to unwind, though saying that to a community full of gamers is fairly redundant I feel.
As far as Oprah being a presidential candidate, I'm sure she'd be good, but the real question is why would she run? At this point, anyone running has to clean up Donald Trump's mess as well as finish cleaning up the mess that Bush left and fine-tune what Obama was trying to do. Another question I feel needs asking is how long will color be a factor? I know racism is a thing, but going into presidency as a minority is fairly dangerous enough as is. You not only have to deal with possible racism from already existing political figures, but also from your own nation as the split is NEVER just Minority vs Majority or Black vs White or whatever categories happen to pop up. That person must also be ready to die at a moment's notice as assassinations are still a very real threat to the life of someone that big.
I know a lot of what I've said can't possibly be achieved by just one person, no matter how great they are, but if that one person can influence how the next person goes about it, and start a chain of having great leaders, then maybe, just maybe, that world of peace won't seem like will never exist. Now, who is that person of greatness....? WEEEEELLLLLL.....