“Any efforts to ban fracking or restrict supply will not remove demand for the resource,” Neil Hansen, Exxon’s vice president of investor relations, said on a conference call with analysts. “If anything it will shift the economic benefit away from the U.S. to another country, and a potentially impact the price of that commodity here and globally.”

Elizabeth Warren and Bernie Sanders, two front-runners in the race to be the Democratic candidate, are keen to stop America’s reliance on fossil fuels, and they also want to end what they say is Washington’s subservience to corporate interests. They also know how to hit Exxon and Chevron where it hurts. Five years ago, both companies produced little crude from fracking and might have even have benefited from a ban if it led to higher oil prices. But now fracking is the fastest-growing part of their global businesses and a key profit driver.

Hydraulic fracturing of shale rock is pushing U.S. oil production to record highs, touching 12.4 million barrels a day in August. Exxon said Friday its output from the Permian Basin in West Texas and New Mexico had boomed by more than 70% in the third quarter from a year earlier. Chevron, a bigger Permian producer, saw its output there climb 35%.

Warren Frack Ban Sparks Angst Among Investors in Texas Drillers

That wave of supply has ensured lower gasoline and energy prices for domestic consumers, bolstered economic growth for states such as Texas and North Dakota, and restored the country to ranks of the world’s major crude exporters.

“It’s really unlocked an economic huge economic benefit for the country, as well as for the companies involved,” Jay Johnson, the boss of Chevron’s upstream business, said during the company’s earnings conference call.

But fracking also has costs, particularly in terms of the climate. Cheap fossil fuels typically mean people use more of them, causing higher emissions. Hansen said that while Exxon shares concerns about climate change, “there are more effective policies” such as a revenue-neutral carbon tax and technology initiatives.

“Any efforts to ban fracking or restrict supply will not remove demand for the resource,” Neil Hansen, Exxon’s vice president of investor relations, said on a conference call with analysts. “If anything it will shift the economic benefit away from the U.S. to another country, and a potentially impact the price of that commodity here and globally.”

Elizabeth Warren and Bernie Sanders, two front-runners in the race to be the Democratic candidate, are keen to stop America’s reliance on fossil fuels, and they also want to end what they say is Washington’s subservience to corporate interests. They also know how to hit Exxon and Chevron where it hurts. Five years ago, both companies produced little crude from fracking and might have even have benefited from a ban if it led to higher oil prices. But now fracking is the fastest-growing part of their global businesses and a key profit driver.

Hydraulic fracturing of shale rock is pushing U.S. oil production to record highs, touching 12.4 million barrels a day in August. Exxon said Friday its output from the Permian Basin in West Texas and New Mexico had boomed by more than 70% in the third quarter from a year earlier. Chevron, a bigger Permian producer, saw its output there climb 35%.

Warren Frack Ban Sparks Angst Among Investors in Texas Drillers

That wave of supply has ensured lower gasoline and energy prices for domestic consumers, bolstered economic growth for states such as Texas and North Dakota, and restored the country to ranks of the world’s major crude exporters.

“It’s really unlocked an economic huge economic benefit for the country, as well as for the companies involved,” Jay Johnson, the boss of Chevron’s upstream business, said during the company’s earnings conference call.

But fracking also has costs, particularly in terms of the climate. Cheap fossil fuels typically mean people use more of them, causing higher emissions. Hansen said that while Exxon shares concerns about climate change, “there are more effective policies” such as a revenue-neutral carbon tax and technology initiatives.