It's true that marijuana use can exacerbate latent or existing mental disorders, but this is rare. Often, marijuana can do just the opposite and help people to recover from emotional problems. There is no evidence that marijuana causes schizophrenia. Another health issue is the carcinogens in the smoke. Firstly, these are avoidable in numerous ways, including vaporization of the THC without burning the plant material, and oral ingestion. Secondly, no correlation between smoking of cannabis and rate of lung cancer has been found. None of these are reasons why the government should be able to stop us from using it. The only person who can be hurt by these things is the person smoking it, and Marijuana is still less harmful than alcohol or tobacco.
	Why should pot be illegal? Some worry that people driving around high on weed will cause a tragic accident. Really, this is not any more likely than a sober person causing a tragic accident. Being high doesn't make people into idiots. They know they're driving while high, and they slow down and pay attention to what they're doing. High people aren't usually willing to drive recklessly or even incautiously. It's true that in a high speed collision, a split second of reaction time can mean the difference between life and death, but the person driving high probably isn't driving as fast. Another thing people point to is marijuana's reputation as a “gateway drug,” or drug which leads first time drug users into harder, more dangerous drugs, like heroin or cocaine. While there is some truth to the stereotype that harder drug users often start with cannabis, cannabis does not necessarily cause people to move on to harder drugs. Correlation does not equal causation. The same junkies probably also started out with alcohol and tobacco before they tried hard drugs. Yes, it is possible to abuse cannabis as with anything else of its kind, but this does not make it a bad thing.
	The fact of the matter is, marijuana was made illegal because of racism almost a century ago, and now remains illegal because of organized crime, the paper industry, the pharmaceutical industry, and other industries that would suffer if they had hemp to compete with. I should say that it is still illegal because not enough people have stood up together at once and demanded change. But this is not the whole story. Many people still harbor negative attitudes toward cannabis, due in large part to anti-pot propaganda. Today's propaganda paints pot users as slacker teens wasting their lives and aging losers crashing their cars into children. Parents are still afraid that if pot is legal, their kids will get hooked. Apparently they don't realize that it is currently easier for high school kids to get weed than to get alcohol. They also don't seem to realize that dealers today often spray their product with strange chemicals or other drugs; there is no guarantee that the bud you buy is safe. 