For some Democratic voters in Pennsylvania, Tuesday's primary election will be more than just a chance to pick preferred candidates for public office - it will be a mini-referendum on the future of the state's downtrodden fracking industry.

Three candidates on the ballot, including Democratic presidential hopeful Bernie Sanders and two Democratic U.S. Senate hopefuls, want to ban or pause the controversial oil and gas drilling technique, splitting an electorate in parts of the state concerned about both jobs and the environment.

A debate over fracking emerged between Sanders and Democratic presidential front-runner Hillary Clinton over the last month, with Sanders calling for a nationwide ban and Clinton pushing a middle-of-the road approach that would allow it with caveats - a stance that has been criticized by more progressive democrats.

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The outcome of the presidential and senate primaries in a state that now the second biggest natural gas producer in America after Texas may reveal how residents of heavily drilled areas feel about an industry suffering from a decline in oil and gas prices.

"Everyone is anxious," said Lois Martin, a sales manager at a store in Washington that sells gear, like steel-toe boots and drill-site clothes, to workers in the fracking industry. "Everybody is waiting for the elections to be over," she said.

The question of a ban on fracking has also emerged as a key issue in the hotly contested race to select a Democrat to run for a U.S. Senate seat in Pennsylvania against the incumbent Republican Pat Toomey.

Two candidates, former U.S. Congressman Joe Sestak and John Fetterman, a small town mayor, have called for a moratorium on fracking. The third candidate, Katie McGinty, the former head of the state’s environmental regulator, has been endorsed by President Barack Obama and Governor Tom Wolf, and is looking for stricter standards on the industry.

"Now is the moment to really do it," Sestak said about a ban, pointing to a slump in oil and gas prices that has left many drill pads idle. "We can’t even pump any more gas out because our pipelines are filled."

McGinty has called that stance a "sound bite", and not a serious proposal.

States like New York and Maryland have already passed moratoriums on fracking while they conduct studies into its environmental impacts.

Fracking - which involves pumping water, sand and chemicals into the ground to free oil and gas reserves from rock formations - is responsible for a boom in U.S. oil and gas production over the past decade that has slammed energy company profits and lowered costs for consumers.

It has also been implicated in ground water pollution, and a rash of small earthquakes in places like Oklahoma and Ohio, raising concerns about its safety.

Opposition to fracking, meanwhile, has risen to an all-time high nationwide of 51 percent, according to a Gallup poll released March 31, from 40 percent a year earlier.

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WEALTHY OVERNIGHT

In many of the most heavily fracked regions of Pennsylvania some residents are not ready for a ban. They are looking for a way to both support the industry while also improving safeguards to protect the environment.

Mark Zabilitzky, a farmer with white hair in his early-sixties, said he leased out mineral rights on his property to a natural gas company four years ago in exchange for around $1,000 an acre and a cut of production royalties.

But the company has not drilled yet, and Zabilitsky is hoping for a rebound in natural gas prices to make it happen before he retires. "I am not too far off of retirement," he said. "We thought we would be wealthy overnight."

He said he appreciates Sanders' devotion to protecting the environment, but thinks fracking can be done safely.

David Spigelmyer, president of the Pittsburgh-based Marcellus Shale Coalition, said calls for fracking bans by Sanders and the Senate hopefuls posed a risk to "mom and pop shops that have provided jobs to our neighbors."

"We have people that want to take us in a dangerous direction," he said at a meeting of landowners in South Franklin township in Washington county last week.