A committee run by the Drug Policy Alliance, which received $1 million from multibillionaire investor George Soros earlier this week, is trying to persuade young voters to show up for a midterm election they might otherwise skip. Democratic activists are watching the initiative to see whether putting similar measures on state ballots in 2012 might boost youth turnout.

"Getting younger voters and progressive voters to the polls Tuesday could well make the difference for this historic initiative to end decades of failed, punitive and wasteful marijuana policies," said Stephen Gutwillig, the California director of the Drug Policy Alliance.

The initiative’s supporters, armed with cash from recent major donations, are targeting young voters who polls show overwhelmingly support legalization with commercials on Comedy Central’s "The Daily Show with Jon Stewart" and "The Colbert Report."

With the election just five days away, the debate over Proposition 19, the marijuana legalization measure, is ramping up on the airwaves with both sides launching new commercials.

The opposition campaign, which has far less money, is running radio commercials. On Thursday, it expanded into the San Francisco market with a new 60-second radio ad. The commercial notes that the major candidates for governor, senator and attorney general, as well as President Obama’s attorney general and Sen. Dianne Feinstein, all oppose Proposition 19. The ad also mocks the initiative as so flawed, its authors must have been stoned.

"Whether you are for legalization or not, it’s not the right approach," said Roger Salazar, a spokesman for the No on 19 campaign. He said the campaign is targeting the Bay Area, where support for the measure is strongest, because there are still many undecided voters. "There’s a lot of Democratic voters up there, and we want to make sure that the voters in San Francisco understand that a lot of the folks they support are opposed to Prop. 19," he said.

Proposition 19 would allow adults 21 and older to possess up to an ounce of marijuana and grow up to 25 square feet. It also allows cities and counties to legalize commercial cultivation and retail sales, and impose taxes.

The 30-second ad on Comedy Central aims to motivate Proposition 19 supporters to vote in Tuesday's election, noting the measure could pass with a large pro-legalization turnout.

"They’re hoping we don’t vote this year," intones a male announcer as the text flashes on screen. "That’s why they don’t talk about Prop 19. How it’ll force the government to stop wasting money on outdated pot laws. How it’ll let the police spend more time locking up real criminals. How it’ll bring up to $2 billion a year to California. But the biggest thing they didn’t tell us about Prop. 19 is that the polls show, if we vote, we win."

The commercials will run Thursday and Friday in the Bay Area, and Friday and Monday in Southern California.

The No on 19 ad says the initiative would put the state in conflict with the Drug-Free Workplace Act. "Prop. 19 could even allow BART engineers and school bus drivers to smoke marijuana right up until the moment they climb into the driver’s seat," says a female narrator, speaking rapidly. "Wow. Maybe the proponents should have waited to celebrate until after they had written the legal language because what they wrote is a jumbled legal nightmare."

In another version that will run intermittently, the narrator, in a reference to pot-induced munchies, says the measure submitted to the secretary of state "smelled like Cheetos."

"This is a serious issue," said Salazar, "but that doesn’t mean you have to be humorless about it."

-- John Hoeffel