WHAT COSTS nearly half a million dollars but gets you nowhere? A failed ballot measure.

Measure 24, a constitutional amendment that would legalize growing and using marijuana in Oregon, failed to qualify for the ballot last week—even after a monumental $427,784 effort. Now the marijuana measure backer, Robert Wolfe, is planning to sue the state, the Mercury has learned, alleging that the elections division is disenfranchising voters by nitpicking petition signatures.

But no matter how his suit turns out, Wolfe's measure joins a surprisingly long list of failed pot initiatives that point to the hurdles facing any group trying to change state drug laws via the popular vote. While marijuana is rather popular in the state (the number of Oregon medical marijuana cardholders and caregivers is now at 81,468), only two of 20 marijuana measures proposed since 1998 have even made it to the ballot—and both failed.

The three measures proposed this year, including Wolfe's legalization amendment, are all variations of previously proposed measures. But only the Oregon Cannabis Tax Act looks poised to finally make the ballot—after four previous attempts flopped.

The causes of those other measures' failures are numerous. But pot reform activists say 2012 is—finally—the year for change. Oregon Cannabis Tax Act spokesman Roy Kaufmann points to polls that show support for marijuana legalization has ticked up to 56 percent nationwide. Plus, he notes, previous measures (like 2010's marijuana dispensary Measure 74) dealt with tweaking the current medical marijuana system rather than proposing straight-up legalization. This year's act would legalize growing, selling, and regulating cannabis and hemp in the state.

"A lot of the pushback editorial boards gave was that an extension of medical marijuana was a gray area half-step," says Kaufmann.

Oregon Cannabis Tax Act backer Paul Stanford, who has worked on several past measures, says previous initiatives didn't run effective or well-funded campaigns.

"Once they got on the ballot, they basically didn't have a campaign, they just disappeared," says Stanford.

John Sajo, who campaigned for 2004's Measure 33, pins pot's hardships on the relatively low turnout of young voters.

"The people who are actively against marijuana are the reliable voters," says Sajo. "We probably made a mistake by putting that up in a non-presidential year."

There's one setback that's undeniable: The cost of getting a measure to the ballot is huge, requiring major backing for even "grassroots" efforts. Look, for example, at the finances behind this year's Oregon Cannabis Tax Act. Nearly all of its $260,469 war chest comes from a political nonprofit called the Campaign for the Restoration and Regulation of Hemp (CRRH). That group's finances aren't clear, thanks to Oregon's non-transparent campaign finance laws, but Stanford, president of CRRH, says 95 percent of their money comes from roughly 60 Presto Quality Care medical marijuana clinics he oversees across nine states. Those clinics bring in millions a year and donate some of their profit to the cause.

Once the measure officially qualifies for the ballot, Stanford says, the nonprofit plans to raise $4 million from private and national donors. They might, too—the oldest biofuels company in the country, Pacific Biodiesel, has a factory in Salem and supports the measure because it would mean legal access to hemp oil they can convert to fuel. Singer and renowned marijuana lover Willie Nelson, an investor in that plant, has already donated more than $10,000 to the campaign.

The other measure—Wolfe's constitutional amendment legalizing marijuana use—had even deeper pockets. That campaign gathered more than $300,000 from a political committee called "Citizens for Sensible Law Enforcement," which itself is substantially funded by the Foundation for Constitutional Protection, a national marijuana-reform group. That money facilitated a massive signature-gathering campaign involving more than 170 paid canvassers. But the secretary of state alleged in April that the campaign was illegally paying petitioners per signature, slapping the campaign with a $65,000 fine and later throwing out 46 percent of their signatures for collection errors (other campaigns had 31 to 42 percent of their signatures thrown out).

"Under Kate Brown, the elections division has implemented extremely punitive, arcane, and complex rules that drive them to disqualify as many signatures as possible from these petitions," complains Wolfe, who hopes a judge will agree that the signature validation system is "rigged against voters."

"We use the same signature verification formula for all initiatives," responds Oregon Secretary of State press agent Andrea Cantu-Schomus. "The formula has been held up in court numerous times."

Though Wolfe worked on 2010's marijuana dispensary Measure 74, he says this is his last: "If I wanted to spend a lot of money to no effect and beat my head into the ground for nine months, I would take up something easier."