re: When will Marijuana be Legal nationwide?

From a quick legal standpoint: The states want to legalize marijuana and claim it is a states right for which they can collect major taxes from. The problem is that marijuana is considered a controlled substance by federal law, which would have to be changed. Now you have state laws conflicting with federal laws. Fed govt claims that Congress has the power under the Commerce Clause (which includes the right to regulate channels, instruments, and substantial effects of commerce and also to prosecute citizens under USC 2814 in a state who violate federal law even if they are abiding by state laws) to stop the legalization of marijuana for non medicinal use. This is because Congress may regulate things if they threaten a national market. There is a national market for marijuana, even though it is illegal in most states, because money does change hands, it is not free and it has the potential to go into the interstate market even though it is intended for personal use. Congress can regulate things even though it can be proved that it is for personal use only and have done so on several occasions such as Wickard v Filburn (famer grew his own wheat, warned that if he produced too much he would get a penalty and did so, court said it impacts commerce because it obstructs increased prices and if all famers did this then the state cant keep prices where they want). Even if something never goes into commerce, it still may be considered in its stream.

Going to be a long road ahead to get the classification changed as they have not been swayed yet.