As much as we all love Pac, he wasn't any more an activist than any other rapper who writes socially conscious rap (like a Talib Kweli).
Pac would have had a long music career and a longer acting career. He almost surely would've branched out into businesses like Jay Z and Puffy have. I believe if he was alive today he would have a position similar to how people view Jay Z, probably even bigger than Jay currently is.
But hey, who knows how much more jail time was in his future, or if he would have lost focus and fallen off like a Snoop. Either way, he wasn't leading a political movement.