Legalize marijuana and reduce the corn farms in the US. The US grows so much corn, we have to find ways to use it just to get rid of it. Majority is for unhealthy reasons like feeding cows (which corn isn't digestible for anyone and produces many health problems in livestock and humans.) or producing High Fructose Corn Syrup which is unhealthy to everyone.
Use the corn farms to produce Hemp which is a healthy alternative for feeding livestock, using the fibers to make paper and clothes, using the oils to make bio-fuels and bio-diesel. You can even use Hemp to make a non-toxic, mold-fire-insect resistant, and energy efficent Brick that can be used to build houses. So many things can be made from Hemp alone.
Taxing Marijuana would produce millions in revenue and decrease jail space.