Government both Fed and State are losing money now that we have taxed and educated our way to the death of the big tobacco. Suddenly those inexhaustible sin tax revenues are no longer there to be spent at will.
I think the major thing keeping pot illegal is how to tax it.
Once that is solved the major hurdle will be out the way.
I think the other hurdle will be people who were raised to think of pot as a wicked scary substance. A lot of people have bought into the notion that cannabis will cause death, destruction and mayhem if it is more available.
That being said, it if was legal I still wouldn't smoke it, I'm fat, lazy and dumb enough already thank you very much.