Who, living, would you class as a genius? Any Why?

John Hume.
For simply doing the VERY complicated to and fro'ing for years (in the background and in public - all under serious pressure) with armed militants and their many complicated issues - and then helping in bringing them eventually to a peace table.

Anyone that can walk the political tightrope for years and do what he had done alone, has to be a genius.
When he was finished, he just went quietly and humbly home to rest with no bigheadness or ego-trip,
What a man! Humble and very clever.