1. Federal spending on drug enforcement has increased over a long history.
2. Marijuana has apparently not yet been linked with lung cancer in a 2006 study but other later studies have indicated some links.
3. Marijuana is associated with potentially serious negative effects on adolescents.
4. Crash rates in states that have legalized marijuana have increased in statistically significant way. However, the states that have legalized it generally have the same or lower total fatalities as the other states (presumably because of non-marijuana-related reasons).
5. Marijuana legalization has been a growing source of tax revenue in Colorado.