Vermont Sen. Bernie Sanders joined three fellow Democrats in urging Attorney General Loretta Lynch to continue its inquiry into “the fossil fuel industry’s climate denial operation,” a day after Senate Republicans called on her to cease any such probe.

“We write today to urge that you view the Republican Senators’ May 25 letter as Exhibit A among the reasons why the Department of Justice should take a full and honest look at possible fraud in the fossil fuel industry’s climate denial operation,” said the Thursday letter.

In addition to Mr. Sanders, the letter was signed by Democratic Sens. Sheldon Whitehouse, Elizabeth Warren of Massachusetts and Jeff Merkley of Oregon.

Ms. Lynch said at a Senate oversight hearing in March that she had referred information on what Mr. Whitehouse described as “the climate denial scheme” to the FBI. Senate Republicans have slammed the effort as an attack on free speech and scientific inquiry.

In their letter, the Democrats argued that “fraud is not protected by the First Amendment,” drawing comparisons between the tobacco industry and oil-and-gas companies that have taken a skeptical view of catastrophic climate-change predictions.

“It would be a sorry world in which corporations engaged in fraud could pull the screen of the First Amendment over any investigation of their fraud,” said the Democrats’ letter.

The Justice Department won a civil lawsuit against the tobacco industry in 2006 using the Racketeer Influenced Corrupt Organizations Act.

“The template for the Department investigating this question, of course, is the Department’s own victory in its civil RICO lawsuit against the tobacco industry,” said the Democrats in their letter. “The Republican Senators’ letter reprises the tobacco lawsuit’s own early history of efforts from Congress to discourage or interfere with that lawsuit in order to protect the tobacco industry.”

Critics have rejected the comparison, arguing that there is far more scientific disagreement on the impact of increased carbon dioxide levels in the atmosphere on the climate than there was on the link between smoking and major health problems.

Ms. Lynch said at the March 9 hearing of the Senate Judiciary Committee that she had referred information to the FBI to determine “whether or not it meets the criteria for what we could take action on.”

Justice Department spokesman Wyn Hornbuckle had no comment Friday on the dueling Senate letters or status of the inquiry.

“We’re aware of the letters. We’ll decline to comment further,” Mr. Hornbuckle said in an email.

In their Wednesday letter, the Republicans argued that efforts to prosecute climate-change skeptics constitute a “blatant violation of the First Amendment and an abuse of power that rises to the level of prosecutorial misconduct.”

The letter was signed by Sens. Mike Lee of Utah, Ted Cruz of Texas, Jeff Sessions of Alabama, David Perdue of Georgia, and David Vitter of Louisiana.

Last week, 13 House Republicans sent letters seeking information from a coalition of state attorneys general, known as AGs United for Clean Power, on their efforts to pursue climate-change skeptics.

Two of those attorneys general — New York’s Eric Schneiderman and the Virgin Islands’ Claude E. Walker — have since issued subpoenas to ExxonMobil. Mr. Walker withdrew last week a subpoena issued to the free-market Competitive Enterprise Institute.

Sign up for Daily Newsletters Manage Newsletters

Copyright © 2020 The Washington Times, LLC. Click here for reprint permission.