In a fiery debate on Thursday ahead of the Democratic presidential primaries in New York and Pennsylvania, Hillary Clinton and Sen. Bernie Sanders faced-off on energy policy, including horizontal hydraulic fracturing, in an exchange that highlighted a gulf in their positions on the issue.

Sanders moved quickly to poke holes in Clinton’s record, pointing to her ties with wealthy donors, oil and gas companies and investment banks. He needs a landslide in New York as Clinton has pulled well ahead in the delegate count and draws nearer to the 2,383 needed to win the nomination. But Clinton refused to back down, essentially saying Sanders’s call for a nationwide ban on fracking and energy-related legislation that he’s championed in the past to curb climate change don’t acknowledge the reality of the situation.

“I don’t take a back seat to your legislation that you’ve introduced that you haven’t been able to get passed,” Clinton said. “I want to do what we can to actually make progress in dealing with the crisis. That’s exactly what I have proposed. And my approach, I think, is going to get us there faster without tying us up into political knots with a Congress that still would not support what you are proposing.”

During his time in the Senate, and since the beginning of his campaign for the White House, Sanders has made it clear that he not only opposes fracking, but he also wants a nationwide ban. He’s advocated strongly for a transition away from fossil fuels to clean energy, and co-sponsored legislation to, among other things, prohibit new leases for exploration and production in the offshore Arctic, Atlantic and Pacific oceans and the Gulf of Mexico.

He supports reducing carbon emissions and establishing a carbon tax, which he pressed Clinton about Thursday, but she didn’t address the issue. During the debate at the Brooklyn Navy Yard, Sanders called climate change “a global environmental crisis of unprecedented urgency,” deeming it an “enemy” that is likely to cause “drought and floods and extreme weather disturbances” that could lead to global conflict.

Clinton seemed to take a more centrist approach compared to Sanders, suggesting that she would likely perpetuate some of the Obama administration’s key energy policies, expressing support for the Clean Power Plan and saying the President deserves “our appreciation, not our criticism” for such efforts.

“I don’t think I’ve changed my view of what we need to do to go from where we are, where the world is heavily dependent on coal and oil, but principally coal, to where we need to be, which is clean renewable energy, and one of the bridge fuels is natural gas,” Clinton said when asked about her time as secretary of state promoting the benefits of fracking. “And so for both economic and environmental and strategic reasons, it was American policy to try to help countries get out from under the constant use of coal, building coal plants all the time, also to get out from under — especially if they were in Europe — the pressure from Russia, which has been incredibly intense. So we did say natural gas is a bridge, we want to cross that bridge.”

Sanders countered by saying “we have got to tell the fossil fuel industry that their short-term profits are not more important than the future of this planet.”

When asked how he would fill a void in the nation’s energy portfolio with a fracking ban and other policy proposals, such as phasing out nuclear power, Sanders said such a phase-out wouldn’t occur overnight. To replace the oil and gas lost with any ban, he would institute a “massive program” to deploy “half a billion more solar panels by the end of my first term and enough clean energy to provide electricity to every home in America within 10 years.” He acknowledged that banning fracking would lead to “economic dislocation,” saying there would be “some people who lose their job,” but added that “it is not their fault that fossil fuels are destroying our climate.”

An “enormous amount of money” would be built into any legislation to help those workers and provide opportunities across the country to help install new renewable energy sources.

That tack might play well in New York said Terry Madonna, director of the Center for Politics and Public Affairs at Franklin and Marshall College in Lancaster, PA. But Madonna said Pennsylvania appears to be a lost cause for Sanders. A recent poll from the Siena College Research Institute of 538 likely Democratic primary voters shows Sanders has narrowed Clinton’s lead in New York to 52-42%

But Madonna said Pennsylvania is “Clinton country.” While Sanders’s rhetoric against the oil and gas industry is not helping him in a state that’s home to one of the nation’s leading natural gas basins, Clinton’s deep ties in the state have her far ahead in the polls. President Bill Clinton carried the state twice, she beat Obama by 10 points in the 2008 primary in Pennsylvania, her father is from the state and she has well-established relationships with state party leaders and national fundraisers in Philadelphia, Madonna said.

“The average voter does not understand what the necessary regulations are to make sure we have clean air and pure water, it’s beyond their knowledge,” he added of voters in the state. “We’re asking them things they don’t know much about. In general, though, they understand that Pennsylvania is an energy state. In general, they’re supportive of fracking, they just want it done safely.”

For the industry itself, this election cycle has been a mixed bag.

“I really don’t think there’s consensus across any of the industry folks I work with as to who would be the better candidate” in either party, one industry consultant said. “The extreme position of Bernie Sanders, however, saying we should ban [fracking] is just so ludicrous in the real world.”

In a Friday blog post, BTU Analytics CEO Andrew Bradford said such a ban would have vast repercussions for energy markets, labor markets, state economies and much more.

But from “the natural gas and power market perspective, banning fracking would make natural gas production drop precipitously, natural gas prices would leap higher which would send the electric generation market into a fuel switching frenzy, where despite the most bullish wind and solar forecasts, king coal would be forced to backfill generation.”

The latest Franklin and Marshall College poll of 828 registered voters shows Clinton with a sizable lead in Pennsylvania. It showed Clinton ahead by 53-28% at the end of March, with 11% undecided. Voters head to the polls in New York on Tuesday, while the Pennsylvania primary is set for April 26, when four other states will hold their contests as well.