States could be test cases for marijuana legalization

The test case instead could be Washington, where voters on Nov. 6 will decide whether to directly confront the federal ban on marijuana and embrace a sprawling plan to legalize, regulate and tax sales at state-licensed pot stores.

Speculation on the potential federal blowback is rife.
Would the Obama administration pick a legal fight over states' rights to try to block Initiative 502? Would federal prosecutors charge marijuana growers and retailers, even if they are authorized by state law?

Or would — as some opponents and supporters predict — federal authorities denounce the law but largely leave Washington alone?
Apparently marijuana legalization is on the ballot in Colorado, Washington, and Oregon, and leads in Washington.