If 18 states have de-criminalized pot, your state would be one of 36% of 50 United States that have passed laws signifying are okay with personal possession of pot; quit trying to make your state seem greater than it really is Den Den
And just because Obama said that they wouldn't go after the STATE that passed the law does not mean that the law officials won't go after YOU who is caught with the product (I am not saying you, due to the fact that I know you don't smoke; just a generalization). Now if the case were to go up past the civil and into a federal court, all the way into the hands of the Supreme Court, the decision would lay in the hands of one of nine people to pass judgment - Hint... None of them are named Obama.
These people have the right to make the federal ruling on your case; to determine if the crime you are charged with will be upheld based upon the decision made on a state level or if the Federal Laws applied will be applicable in your case. According to the track record of the Supreme Court system though, they tend to side with Federal Laws over state issued ones. The ONE point going for the person in something like this will be that the majority of these cases will never see the light of day in a courtroom, yet my point still remains that just because your state says "go ahead, it's okay with us" doesn't mean that the feds don't have the right to rule your case based upon Federal Law, which still qualifies Marijuana as a Class 2 Narcotic.