A massive majority of 85 percent believes cannabis should be permitted for medical use, with a doctor's prescription, the poll found. Voters back decriminalizing pot - 59 percent to 34 percent - making possession of small amounts a summary offense, like a traffic ticket. They are more divided on outright legalization: 48 percent in favor, 42 percent opposed.
"Marijuana," said Joseph Morris, director of the applied politics center at Erie-based Mercyhurst, "has just become an accepted, household thing in many ways. . . . It is seen as closer to cigarettes and alcohol than harder drugs like cocaine and heroin.
"We are quickly approaching a critical mass of states that will legalize marijuana to some degree," Morris told The Inquirer.
While Colorado and Washington have legalized recreational pot use, 20 states (including New Jersey) and the District of Columbia have approved using marijuana for medical purposes - even though it remains illegal under federal law for any reason. Seventeen states have decriminalized weed.
Hanger, a former state environmental secretary, says that, if elected, he would first push to decriminalize possession, then work on legislation to permit medical marijuana, and follow up by 2017 with a legalization regime that would regulate and tax the drug.
"I reached the conclusion that the current prohibition policy is a disaster for taxpayers, a disaster for patients who need medical cannabis," Hanger said in an interview. "And it promotes racial injustice."
He likes to point to a 2013 study of marijuana arrests in Pennsylvania, conducted by the American Civil Liberties Union, that found African Americans 5.19 times more likely than white people to be arrested for possession, even though health surveys have estimated that the two groups use marijuana about the same rate.
The ACLU also reckoned the state spent about $100 million a year to arrest and lock up pot users.
Most of the other Democratic gubernatorial candidates favor medical marijuana and decriminalization of possession. But they draw the line at full legalization.
Mercyhurst's statewide poll, conducted Feb. 17-26, found support for medical marijuana across the demographic, partisan, and ideological spectrums. On other questions, those favoring decriminalization or full legalization tended to be younger, Democratic, liberal, and libertarian, with opponents tending to be older, Republican, and more conservative.
The survey of 495 registered voters was conducted by telephone interviewers. Pollsters said the results were subject to a margin of error of plus or minus 4.4 percent.
Corbett, a career prosecutor before he was elected governor, opposes medical marijuana - or any other relaxation of the laws. One radio ad suggests his campaign was betting that most voters would shun a pro-pot candidate.
In the ad, which attacks four of the Democratic hopefuls, a mention of Hanger is accompanied by the sound of a cuckoo bird. An announcer says Hanger "doesn't sound like someone we want in charge of our public schools."
Education funding, jobs, and the economy are the top issues in the election, according to polls, but Hanger said he would take credit for influencing the debate: "I don't think this issue would have been raised if I hadn't put it on the table."
The backdrop is rising national support for legalization. A Gallup Poll in October found that a majority of Americans - 58 percent - for the first time favored legalization of recreational marijuana. Democrats, independents, and younger voters especially were in favor.
Roger J. Cohen, Hanger's political director, said the marijuana issue was "central" to the candidate's strategy. With less money on hand than rivals, and relatively low name recognition, Hanger is counting on a passionate base and on boosting turnout among young voters and African Americans in a crowded May 20 primary that could be won with as few as 300,000 votes.
Cohen noted that last week's Harper Poll put Hanger's support at 7 percent, unchanged from his standing in the company's survey in November. Other candidates shed support as Wolf, having financed a barrage of early TV ads, took the lead in the more recent poll.
"What that tells me is a large share of the support for other candidates was soft, and it migrated," Cohen said. "We held our position, and that means our supporters are committed - and a lot of that has to do with the legalization issue."
Hanger's stance drew some of the loudest applause at a Nov. 23 candidates' forum. But that was a young audience of union members and community activists at Temple University. Political analysts doubt the potency of pot statewide.
"There's a risk that his emphasis on it makes him look more like a fringe candidate," said John Kennedy, a political scientist at West Chester University, who specializes in Pennsylvania elections.