It's even safer to say that this particular character description is completely unnecessary to the plot one way or another.
That being said, he did appear to look rather "regal" in ROTS, and his standing in the Senate would really have no bearing on his political state on his homeworld. Why couldn't the king - or one of the kings - of Alderaan also be a galactic senator? Perhaps someone was just too darned angry to bother contemplating such a concept...