Unfair? No. It's actually more fun to try and guess.
Considering that hundreds of historical and contemporary figures could have said this -- possibly even an avant-garde artist! -- it's harder simply to guess without knowing, but hey...
I probably should have stated my reasons for guessing TR.
He was very self-confident.
He seldom apologized, in public. His private life was different.
He was a doer rather than a talker, though he was very eloquent.
He had military experience, so I can see him fighting political battles with a touch of military thought and terminology.
He was the police commissioner for New York City, and also a famous trust-buster. Street thugs and trusts are two groups I can see him opposing with no retreat, no explanations and no apologies. He made them howl, too.