Nucky Thompson is not the guy you'd wish to do business with. Of course not. He could kill you in a second if he finds a good reason to do it. Actually, most of the characters in Boardwalk Empire would do the same.

In the season 3's premiere Nucky Thompson points his gun towards a guy who tried to steal from his alcohol store. He says to him:

"You've got a family, kids to take care of... you'll do anything, which is why I'm not angry [...]. You steal things for a living. Isn't that correct? [...] I'm not angry Nate. You were only doing your job."

"Thank you, Mr. Thompson," replies the thief.

Then, Nucky order his men to untie him. The man feels relieved.

"Oh, but, before you do, put a bullet in his f*** head."

Steve Buscemi in Boardwalk EmpireCredit: boardwalkempire.wikia.comNucky is telling the truth, he respects a man who does his work. But he has to do his job as well. There's no room for sympathies. Specially when sympathies, and even family, tried to put a hole in his head in previous occasions.

This sums up pretty well what kind of character is Enoch "Nucky" Thompson. He cares about Margaret and the children—though he seems to care less and less overtime. He has a heart, but he doesn't let it interfere with his job.

Characters like Nucky keep things real. Like, let me think... Vic Mackey in The Shield, Dexter, Walter White in Breaking Bad, or any character in Battlestar Galactica. They must take some decisions for the greater good, for their families, for their cause. Whatever it may be.

Maybe they are wrong, but you still feel a kind of empathy towards them because you end up understanding their motives. We are not flat characters from a story book. We are complex.

A TV character shouldn't be any different. And that makes the story more enjoyable in my opinion. We need realistic TV characters that make us think and offer us a new perspectives on things.

Haven't you heard or experience that complicated relationships leave the deepest marks? This happens in a relationship, but maybe it's also true for making a TV character memorable.
Anyway, don't expect Nucky's story to be predictable—you can't say that about the show so far—just because this character is based on a real person. There's a reason why he is called "Thompson" and not "Johnson", like the real gangster.