Diane Manchester's multiple sclerosis forced her to retire from the Phoenix Police Department, where she worked as a civilian administrator. Now she often breaks Arizona law by using marijuana to alleviate tremors and other symptoms of her illness.

So Manchester has joined a campaign to make Arizona part of a Western trend: Nine of the 14 states that do allow marijuana use for medical reasons are in the West, including Alaska and Hawaii.

The Arizona Medical Marijuana Policy Project plans to use Manchester in TV ads for a ballot initiative. The group has manpower and money, recruiting about 600 people to circulate petitions and paying them $1 for each signature. They've already gathered around 240,000 signatures -- about 100,000 more than required -- so the initiative will almost certainly appear on the November ballot.

And Arizona voters will almost certainly approve it. They passed medical marijuana initiatives in 1996 and 1998, but those were poorly written and never panned out. This time, campaigners claim to have bulletproof language, honed by plenty of previous experience in Arizona and other Western states.

That's because the West is Medical Marijuanaland. The movement's first big win was in San Francisco in 1991, when voters approved a local ballot measure. In 1996, Californians approved the first statewide measure that stuck. Today in the region, only the most conservative states -- Utah, Idaho and Wyoming -- have not joined up.

Western traits -- libertarianism and high rates of drug use -- help explain the region's enthusiasm. Increasing evidence that marijuana can alleviate suffering has also provided a boost, and the movement has powerful backers, chiefly two billionaires, investor George Soros and Progressive Insurance CEO Peter Lewis.

The movement's main obstacle has been the federal government. The U.S. Supreme Court ruled in 2002 and 2005 that citizens can't overrule federal anti-pot laws. Clinton- and Bush-era federal drug agents conducted sporadic crackdowns on growers, dispensaries, clinics and caregivers, causing anxiety and uncertainty in places that have legalized medical marijuana.

President Obama may or may not be easing up. Some of his top Justice Department officials have told federal agents not to bust dispensaries that comply with state laws. That has inspired a surge in the number of patients and dispensaries. But Obama still has former "Bush hacks" in key enforcement roles, says Dale Gieringer, head of the California chapter of the National Organization for Reform of Marijuana Laws, and the feds continue to raid some Western dispensaries.

So do local cops, because state and local laws have created "a chaotic patchwork" that encourages people to disregard any limits, says Allen St. Pierre, head of the national NORML group. Washington and Oregon allow patients 24 ounces of dried leaves, while California's limit is eight ounces, and Colorado's is two, according to NORML. In some places, patients can smoke in a dispensary; in others, that's not allowed. Many cities are imposing moratoriums on new pot shops while they devise regulations to limit their number and possible spread into residential neighborhoods. Los Angeles even has vending machines: Patients join a collective, enter kiosks with keys, and -- applying their thumbprints as an identity check -- buy marijuana (including brownies) 24 hours a day.

And the movement continues to grow. Medical marijuana has become a formidable industry, with schools that offer training in how to grow and market it. Companies are making millions, even joining chambers of commerce.

The West might even lead the next big leap. Marijuana businesses and entrepreneurs are promoting a California initiative that would legalize marijuana for all uses and impose a sales tax to help that state's budget crisis. California's petitioners turned in 700,000 signatures in January -- 260,000 more than required -- so their initiative will probably qualify for that state's ballot.

Polls indicate that 56 percent of California voters support full legalization. That percentage might shift once the propaganda machines throttle up. Still, as a scruffy musical poet sang in the 1960s, the times they are a-changin' ...