Marcellus Shale Press Coverage

A nasty row that erupted between Hillary Clinton and Bernie Sanders over oil and gas industry donors last week is catapulting the issue of climate change into the race for the Democratic presidential nomination as it moves to New York, where an army of activists upstate is driven by opposition to drilling.

Mrs. Clinton has moved steadily left on the issue, under pressure from Mr. Sanders and his progressive allies, but she continues to come under assault, posing new challenges for her as the race moves to more liberal Northeastern states.

Last week, her mask of composure slipped when she angrily replied to a Greenpeace activist in Purchase, N.Y., “I am so sick of the Sanders campaign lying about me.”

Climate change is a powerful issue for voters in the Democratic base almost everywhere. But it has especially inspired grass-roots progressives in upstate New York, who fought — and won — a yearslong battle against fracking for natural gas.

Even after Gov. Andrew M. Cuomo banned fracking statewide in 2014, many activists — who call themselves fractivists — remain on the front lines of climate fights, and many are skeptical about Mrs. Clinton because of views she held in the Obama administration and earlier, as a New York senator from 2001 to 2008.

Concerned about her prospects upstate, she plans a heavy schedule of campaigning in the region before the April 19 primary, realizing she can no longer count on voters there as confidently as when she earned their support in her two Senate races, when she focused largely on economic issues.

“We now have literally thousands of fractivists who are battle-tested, who understand the politics of these issues,” said Walter Hang, an activist in Ithaca, N.Y. “And they have zero inclination to give away their vote without firm commitments.”

Both the Clinton and Sanders campaigns are said to have studied the progressive Democratic primary challenge to Mr. Cuomo two years ago by Zephyr Teachout, an unknown law professor who won a surprising 33 percent by challenging Mr. Cuomo from the left, partly by highlighting her staunch opposition to fracking.

Ms. Teachout carried counties on the Pennsylvania border and in the Finger Lakes region, where grass-roots anti-fracking groups mobilized voters.

The fracking battle is over, but the activism remains. Mrs. Clinton’s supporters are frustrated that climate activists are skeptical after she rolled out an ambitious renewable energy plan last year, more aggressive than Mr. Obama’s Clean Power Plan.

On Sunday, Mrs. Clinton defended her record on climate issues in Congress and as secretary of state, and said the Sanders campaign’s claims had been debunked. “I feel sorry sometimes for the young people who, you know, believe this,” she said on NBC’s “Meet the Press.” “They don’t do their own research.”

Since the start of the campaign, Mrs. Clinton has moved strikingly to the left on climate issues, including opposing the Keystone XL pipeline, offshore drilling and, indeed, most forms of fracking, a drilling technique also known as hydraulic fracturing.

In a debate last month in Flint, Mich., she said she would severely regulate fracking.

“By the time we get through all of my conditions,” she said, “I do not think there will be many places in America where fracking will continue to take place.”

But Mr. Sanders, a self-described democratic socialist, had a snappy retort: “My answer is a lot shorter. No, I do not support fracking.”

The absolutism of Mr. Sanders’s position on this and other climate issues — as well as the fact that Mrs. Clinton arrived at her views under pressure from the left — has made many activists mistrustful of her and supportive of Mr. Sanders.

Alarmed by reports of potentially catastrophic polar ice melting and other disruptions, many environmentalists believe only a rapid transition to renewable energy is acceptable.

“We’re in the middle of a climate emergency, and have to keep all the fossil fuels in the ground,” said Sandra Steingraber, a scholar in residence at Ithaca College and an activist who supports Mr. Sanders. “Hillary Clinton has definitely shifted her positions. Whether she shifts them again should she become the Democratic candidate in a general election and softens them, that’s the question I hear people wondering about.”

As secretary of state, Mrs. Clinton pioneered a program to promote fracking around the world, as a way to encourage the use of cleaner-burning natural gas and to reduce Russia’s political leverage from its huge gas resources.

Fracking involves pumping water and chemicals deep in the ground under high pressure to blast rock and release gas or oil. The technology unleashed a United States energy boom beginning a decade ago, including the conversion of many coal-fired power plants to cheaper — and cleaner — gas.

Natural gas provides 33 percent of the nation’s electricity, up from 18 percent in 2005, according to the United States Energy Information Administration.

Mr. Obama has championed natural gas as crucial to his Clean Power Plan, seeking to cut by a third greenhouse emissions used to generate electricity by 2030.

Many energy analysts say that an outright ban on fracking, before wind and solar power are feasible at scale, will drive the country back to coal.

“Why not use a relatively clean fuel that’s low cost until it’s not needed,” said Alan Krupnick, a senior fellow at Resources for the Future, a nonpartisan research group in Washington.

He said Mr. Sanders’s call for an outright fracking ban, and Mrs. Clinton’s support for regulations so tough drilling would largely cease, were both unrealistic because most fracking is regulated by states, not Washington.

Mrs. Clinton’s step back from fracking is just one of several reversals on energy and environmental issues she has made since coming under pressure from progressives. Her decision to oppose the Keystone XL pipeline came in September, after she had avoided the issue repeatedly over the summer.

Her position on offshore drilling has also evolved. As secretary of state, Mrs. Clinton was asked to comment on an Interior Department proposal to expand offshore drilling in the Arctic Ocean and in the Gulf of Mexico. In a January 2012 letter, provided to The New York Times by the Republican National Committee, she wrote to the interior secretary, Ken Salazar, that the State Department had no comments to offer on the plan.

Now, as a presidential candidate, she has been a vocal opponent of offshore drilling. Last year, after the Obama administration moved forward with plans on new drilling in the Arctic and off the southeastern Atlantic coast, Mrs. Clinton came out against the plans, a move that was seen as an effort to court the progressive wing of her party.

The spat between the two campaigns over donations from the oil and gas industry, which quickly overheated last week, came as polls have tightened in New York, which Mrs. Clinton once led by a large margin.

On Friday, Mr. Sanders demanded that Mrs. Clinton apologize for accusing his campaign of lying by saying she took large sums from fossil fuel donors.

According to the Center for Responsive Politics, the Clinton campaign has received about $308,000 from individuals who work for oil and gas companies, less than 1 percent of her total donations.

The Sanders campaign points to a Greenpeace analysis claiming that in addition, oil and gas lobbyists directed more than $4.5 million to her campaign and to a “super PAC” supporting her.

But the lobbyists represent numerous industries, not just oil and gas, and the suggestion of a quid pro quo is shaky: Mrs. Clinton has pledged to end subsidies to the fossil fuel industry to pay for her ambitious climate plan.

Although fracking and other climate issues may sway primary voters in New York, they seem less likely to in the next delegate-rich state to vote, Pennsylvania, which has a large fracking industry developed under former Gov. Ed Rendell, a Democrat. Last month in Ohio, which has also benefited from the energy boom, Mrs. Clinton easily defeated Mr. Sanders

Republican candidates have promised to make Democrats’ tough stands against fossil fuels an issue in November. Donald J. Trump has said he can win New York as the Republican nominee because of the economic cost of the fracking ban, which he opposes. Last month he said that thanks to fracking, people across the border in Pennsylvania drove around in Cadillacs.