FILE - In this Oct. 22, 2015, file photo, workers tend to oil pump jacks behind a natural gas flare near Watford City, N.D. Since Donald Trump took office, America’s exports of liquid natural gas and crude oil have surged, rivaling the likes of Saudi Arabia and Russia. To achieve “energy dominance,” the Trump administration has taken its cues from an unlikely source: the Obama administration. (AP photo/Eric Gay, File)

FILE - In this Feb. 5, 2015, file photo, the Anthem logo hangs at the health insurer's corporate headquarters in Indianapolis. Federal officials say the nation’s second-largest health insurer will pay the government a record $16 million to settle potential violations of privacy requirements in a 2015 case that still stands the biggest health care hack in U.S. history. (AP Photo/Michael Conroy, File)

FILE - In this Tuesday, Oct. 14, 2008, file photo, Pittsburgh Penguins' Eric Godard, left, and Philadelphia Flyers' Riley Cote (32) fight in the first period of an NHL hockey game in Pittsburgh. As Cote took and delivered countless punches over more than a decade of junior and pro hockey, he was eager to avoid painkillers. Now a handful of years into retirement, Cote is a proponent of cannabis and its oils as an alternative to more addictive drugs commonly used by athletes to play through pain. (AP Photo/Gene J. Puskar, File)

FILE - In this Thursday, Oct. 4, 2018, file photo, Sen. David Perdue, R-Ga., arrives on Capitol Hill, in Washington. A Georgia Tech political group says Perdue snatched a phone from a student who was video recording while asking the Republican lawmaker a question about Georgia's governor's race. In a statement, a Perdue spokesperson said the senator thought he was being asked to take a picture, so he grabbed the phone to take a selfie. (AP Photo/Alex Brandon, File)

FILE - In this Aug. 28, 2018, file photo, Rep. Kyrsten Sinema, D-Ariz., talks to campaign volunteers at a Democratic campaign office in Phoenix. As the November elections near, Democrats are focusing on health care. It's been a constant drumbeat since the GOP launched its effort to repeal the Obama-era health law and is the subject of the greatest share of political ads on television now. It's a top issue in campaigns from Virginia to Nebraska to California, and especially in Arizona, where Democratic Rep. Kyrsten Sinema has made it the foundation of her Senate campaign. (AP Photo/Ross D. Franklin, File)

Former New York Mayor Michael Bloomberg talks to a woman who lost her daughter to gun violence after speaking at a rally at City Hall in Nashua, N.H. Saturday, Oct. 13, 2018. (AP Photo/ Cheryl Senter)

This photo provided by the United States Geological Survey shows a female Pacific walrus resting, Sept. 19, 2013 in Point Lay, Alaska. A lawsuit making its way through federal court in Alaska will decide whether Pacific walruses should be listed as a threatened species, giving them additional protections. Walruses use sea ice for giving birth, nursing and resting between dives for food but the amount of ice over several decades has steadily declined due to climate warming. (Ryan Kingsbery/U.S. Geological Survey via AP)