Assassin, Cloning is VERY possible, and it is also very ILLEGAL in this country. All you need is a DNA strand and it's on...they've cloned sheep and shit, and I think they recently did a cow...
Caput, have you tried cloning a primate, or a human for that matter? You would be surprised what scientists could do that you don't know about. It's easy to say you can't clone a primate or a human, because nobody wants people to do it, it would cause havoc in the future...
As far as Pac just being back, that's irrational. A clone would start out as a baby, not a walking 25 year old 2Pac...just like everybody else on this planet.
Regardless, it would be a stupid fuckin idea...