Less than two hours after Kamala Harris was named Joe Biden’s running mate, President Donald Trump had cast the California Democrat as an oil industry and fracking foe. “She is against fracking. She’s against petroleum products,” Trump said at a White House news conference Tuesday. “I mean, how do you do that and go into Pennsylvania or Ohio or Oklahoma or the great state of Texas? She’s against fracking. Fracking’s a big deal.”

Harris’s positions on the issue put her to the left of Biden, who has made clear he would not seek an outright ban on fracking, which could only be imposed through congressional action. Nevertheless, Harris and Biden have both promised to curtail oil and gas development on federal lands and waters managed by the U.S. government. And a senior campaign official reiterated last month that Biden would block new fracking on federal lands.

The “fracking” technique is used to coax oil and gas out of some 95% of U.S. wells today, and Trump has been touting his support for the industry as he campaigns for a second term in Pennsylvania and other swing states.

Biden’s energy agenda was already “setting up to be the greenest in U.S. history,” but adding Harris to the ticket signals the Biden administration would “aggressively” pursue its policy goals, ClearView Energy Partners said in a research note to clients.

Some oil industry figures already fearful of Biden’s environmental agenda worry Harris would bolster his resolve to combat climate change and stifle fossil fuel development, including through regulations making them more expensive to produce. But industry advocates plan to emphasize the importance of oil and gas as an engine driving the U.S. economy and critical to its post-pandemic recovery.

“The oil and gas industry represents about 8% of the American economy,” and is “a very important component of our recovery,” American Petroleum Institute President Mike Sommers said by phone. “The world looks a lot different behind the desk in the Oval Office than it does on the campaign trail, and we’re an industry that represents 10 million American workers and will be a key part of that recovery.”

The oil and gas industry faces significant headwinds, not least from the historic drop in demand caused by the coronavirus pandemic. Gas companies seeking to build new pipelines have been stymied in court recently, and some economists have argued a more effective recovery plan would involve green-friendly policies.