In a side-by-side comparison with any other recreational drug, marijuana is always the lesser of two evils. Even with societies "safe" recreational drugs, alcohol and tobacco, a laundry list of side effects and chronic diseases far outweighs any benefit or fun to be had. Alcohol is one of the only recreational drugs on earth with a potentially fatal withdrawal. Lifetime consumption of tobacco inevitably leads to heart disease, organ failure, or cancer. But we can freely purchase these poisons from a grocery store. This does not make sense by any stretch of the imagination or twisted logic. Marijuana has been proven time and time again to have no physical ill effects (allergies exempt), minimal psychological effects, minimal effects on driving, no possibility of fatal overdose, and neuroprotective effects. It actually undoes some of the damage done by chronic alcohol abuse. If marijuana were legalized, regulated, and taxed like tobacco, it would be a cash cow for the government.
The primary motive for marijuana's continued prohibition is the United States' privatized prison system. Profit directly correlates to the number of prisoners held. This means that it is in the prison owners' collective interest to lobby to keep these laws in place. 45,000 americans are in prison right now for marijuana possession charges. At approximately $36,000 per year, this equals almost 1.5 billion dollars a year spent to keep stoners behind bars. (And this is not counting all the money spent on the 800,000 marijuana arrests made). The United States Government spent 15 billion dollars on the War on Drugs in 2010, and they have nothing to show for it.
One could say William Randolph Hearst was the grandfather of the prohibitionist movement. Marijuana posed a threat to the paper industry, of which Hearst had significant holdings in. He spent vast sums of money on a lifelong slander campaign against marijuana, claiming it was a dangerous, violent drug that would cause white women to seek relations with "negroes and mexicans." He succeeded. To this day, there are programs dedicated to scare the general public away from marijuana. Prohibitionist propaganda today claims that marijuana has 4 times the tar of tobacco, causes lung cancer, and increases risk of a heart attack. These have been repeatedly disproven by both funded and independent studies. If consumed orally, no ill effects are even possible, other than consuming more than intended. The founders of America were even proponents of marijuana consumption, Thomas Jefferson has been quoted as saying "Some of my finest hours have been spent smoking hemp on my back veranda and observing as far as my eye can see."
In conclusion, the war against marijuana has cost the United States many billions of dollars, and has gotten us nowhere. Many lives and dollars would be saved if marijuana was legalized and regulated like tobacco or alcohol. There is no reason whatsoever to keep marijuana illegal, as this only puts more money in the pockets of the gangs and cartels. Legalizing marijuana would save lives, create new jobs, and give people a new, safer social vice.