Legalize marijuana throughout The United States.

Hello,
Recently I have been doing research on legalizing marijuana and I think it can actually improve the economy in many ways. There are pages that have debates about it, for example http://www.debate.org/opinions/would-legalizing-marijuana-help-the-economy
One thing I don't understand is why legalize tabbacco?
That can actually kill people which is worst than the effects of marijuana. If tobbacco can kill and it is ok for "we the people" to do, why not marijuana?
Not only will it help the economy but maybe it will decrease drug smuggling on the weed part. If it is legal then people wont go through all the ilegal troubles. All they need to do is go to medical shop and get what they need.