Signaling that Washington State may see a push for legalizing marijuana unlike any state before it, New Approach Washington deposited $1 million in new contributions last week and booked nearly $700,000 in television commercials to pass Initiative 502, says campaign manager Alison Holcomb. She expects "maybe as much as another $2 million" in contributions in the coming weeks, largely for ads targeting swing key voters.

Even California's infamous pot measure, Prop 19, which failed in 2010, petered out of cash with a total haul of about $4.5 million. On the other hand, Washington State is one-seventh the size and has fewer media markets, yet these donations may put I-502 on track for a $5 million or $6 million budget.

Why the big donor support? The latest windfall of cash follows a successful trial ad campaign in August, Holcomb says. Polling research last month found that the August TV commercial—depicting a mom endorsing marijuana legalization even though "I don't like it personally"—was persuasive with an essential female bloc. Holcomb explains, "We specifically wanted to talk to women about marijuana legalization. That there are donors willing to fund a fall campaign speaks to the fact that the ads were successful." She wouldn't divulge details of the polling.

Last week, New Approach Washington received donations, according to Holcomb, from former Progressive Insurance CEO Peter Lewis ($670,000), local philanthropists James and Cody Swift ($300,000), and Washington resident Carrie Rhodes ($30,000). The campaign reserved $688,000 worth of television time for the week running up to the election, Holcomb says, adding "I would love" to run four weeks of ads around the state.

Recent polls show I-502 ranging from 50 percent support (with a 12-point lead over opposed voters) to 57 percent support (with a 23-point lead).

No opposition campaign has been filed, but, historically, the White House drug czar and other federal officials campaign in the last weeks before elections to seed concerns about legalizing marijuana.