Doremus Jessup is the main character of
Sinclair Lewis's 1935 novel
It Can't Happen Here. He is by profession a small-town newpaper editor; politically, he might be best described as
radically moderate; physically, he is a
middle-aged man not overly concerned with his health. Lewis wanted to make his hero a moderate
intellectual who everyone could
relate to and everyone could like.
His nickname, "Dormouse", sums up his apparent character, but he becomes more and more rebellious against the new system. As the book progresses, it seems the only sane person left in the country is Jessup himself.
Basically, he's just a really cool guy. Go read the book.
Compare: Buzz Windrip/Huey Long, Bishop Prang/Father Coughlin.