There is plenty of medical evidence that weed can help people with a myriad of medical conditions and helps them control their pain. The government also needs new revenue streams, so why not legalize something that helps people and causes no long term harm? Criminalizing it just doesn't make sense.
Legalizing marijuana, a drug that is not very dangerous, will hurt the drug cartels in South America immensely. When people are able to buy it legally, they will not risk buying their marijuana illegally. Taxing marijuana can also be a very significant source of income for local governments, and the money can be put to good use.
There is no reason for marijuana to be illegal. Smoking marijuana doesn't harm anyone, except for (possibly) the person who is smoking it. Other substances are legal, despite being proven to be very harmful to the user. In fact, cigarettes can cause harm to other people who are not smoking (secondhand smoke), so if cigarettes are legal, marijuana should definitely be legal.
I support the legalization of all drugs. It takes away the criminal aspect of the whole scene. Marijuana is certainly at the low end of the totem pole when it comes to harmful substances. People should just let people consume what they want to in the privacy of their own home