Weed should be legal in the US. Nothing harmful comes from the drug, so studies have said, and it has no bad side effects that make people go all loony. Nicotine is more addictive and unhealthy and has years of evidence that shows that it creates a problem with cancer. My theory, along with a lot of other law enforcement minded kind of people is this:
Make marijuana legal, and tax it. The country gets another source of income from the people, which could help raise money for such things as health care, roads, city parks, rejuvenation of bad parts of cities, and almost any other thing that you can imagine that the government takes part in.
The second part of this would be ending the Drug War. For so long now, US has fought this war with the drug lords of Mexico. Eliminating the illegal drug by making it legal would make so many of the drug lords lose business that it could possible shut them down, or at least take a hit for quite some time. Ending this drug war should be one of the top priorities within the government, as well as making money/income without raising taxes on middle to poor Americans.
I personally think people shouldn't smoke marijuana because it is a mind altering drug that can affect your ability to work, operate a car, and most everything in life. People will say it just makes you sit there and do nothing at all, but that's my point. Instead of getting out there and working on a job, you are sitting there at home forcing someone else to pick up the slack left behind by you. So, while I believe that you shouldn't smoke anything that alters your perception of reality, I also don't think people should do anything that will harm you like nicotine or do chew.