Washington voters made their state the first in the nation to legalize recreational pot use on Tuesday, setting up a showdown with a federal government that backs the drug's prohibition.  

The measure sets up a system of state-licensed marijuana growers, processors and retail stores, where adults over 21 can buy up to an ounce. It also establishes a standard blood test limit for driving under the influence.  

Legalization could help bring in hundreds of millions of dollars a year in pot taxes, reduce small-time pot-related arrests and give supporters a chance to show whether decriminalization is a viable strategy in the war on drugs.  

Read More at Oregonlive.com: http://www.oregonlive.com/politics/index.ssf/2012/11/washington_measure_502_marijua.html