When the history is written, this won't even be close. Obama will be a top 20 President, and Trump will likely be at the bottom.
I think Obama had his mistakes and learning curve, but he always kept a cool head & was a steady leader throughout his admin. When there was a crisis, and Americans look to their President, he was articulate, thoughtful & calm.
Trump is the opposite. Always emotional & reactive, impulsive, contradicting himself, on the attack & completely unpredictable. Really, a lunatic by comparison.