Marijuana-based products are displayed at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

A bottle of a marijuana-based product is seen at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Marijuana is displayed at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Marijuana is weighed at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014.
REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY BUSINESS) 

Marijuana buds are seen at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

A menu display is seen at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Co-owner Troy Moore prepares packaging at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Manager Selena Toomey weighs marijuana at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Co-owner Troy Moore measures marijuana at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

Co-owner Troy Moore removes a jar of marijuana from the shelf at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014.
REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY BUSINESS) 

Co-owner Troy Moore handles product at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014.
REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY BUSINESS) 

Co-owner Troy Moore (R) hands product to customer Karen Shameklis at "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014.
REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY BUSINESS) 

Kevin Shameklis (L) looks at marijuana-based products as manager Selena Toomey looks on at the "Oregon's Finest" medical marijuana dispensary in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

A sign along a sidewalk in front of the "Oregon's Finest" medical marijuana dispensary is seen in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH) 

The store front of the "Oregon's Finest" medical marijuana dispensary is seen in Portland, Oregon April 8, 2014. Over 20 Oregon cities and counties are moving to temporarily ban medical marijuana dispensaries ahead of a May deadline, reflecting a divide between liberal Portland and more conservative rural areas wary about allowing medical weed. Portland, Oregon's largest city, already has a number of medical marijuana clinics and has not moved to ban them. Picture taken April 8, 2014. REUTERS/Steve Dipaola (UNITED STATES - Tags: DRUGS SOCIETY POLITICS HEALTH)