My thoughts on legalizing Marijuana

Some states in our great nation have legalized Marijuana, but in other states it is illegal. those that are caught within legalized states will not be prosecuted, however in others they will be. What is the piont in only legalizing something in one part of the nation? People that use and are in possession of  Marijuana can just travel to another state and it will be legal. There are people out there that abuse the drug and on the other hand people who need it for medicinal purposes. There are a million different points you could make for and against legalizing it. In my perspective they should either band or legalize it in every state instead of our nation being split up.