Attorney General William Barr speaks during a press conference at the Dirksen Federal Building in Chicago in this Sept. 9, 2020, file photo. Credit: Pat Nabong / Chicago Sun-Times via AP

WASHINGTON — Attorney General William Barr has repeatedly floated a conspiracy theory that other countries may distribute counterfeit mail-in ballots to sway the November election. That’s virtually impossible, according to election officials, ballot-printing companies and political scientists.

Yet it’s a persistent argument from Barr, and it echoes Russian claims designed to undermine trust in the U.S. presidential election.

The attorney general advanced the theory of a foreign adversary mass-producing U.S. ballots at a House Judiciary Committee hearing and in television interviews. Pressed for evidence, he told CNN this month that he was “basing that on logic.”

Those who know vote-by-mail best say that counterfeiting ballots on a scale that could affect a presidential election would be logistically impossible given safeguards already in place as well as how vote-by-mail works. The process requires exacting details, from the paper stock that’s used to listing the ballot measures and candidates that vary from one precinct to another.

“You would basically have to reproduce the entire election administration infrastructure atom for atom in the middle of Siberia in order to have any chance of doing that,” said Charles Stewart III, an elections scholar at the Massachusetts Institute of Technology.

More broadly, Barr has echoed President Donald Trump’s unsubstantiated claims that the November election may be “rigged” because Democrats are promoting the use of mail-in ballots in response to the coronavirus pandemic. The Justice Department declined further comment on the attorney general’s position.

Although there’s no evidence of efforts to counterfeit ballots in any past elections — or this one — U.S. intelligence officials have found that Russia is promoting criticism of vote-by-mail, including claims of foreign interference.

An intelligence bulletin issued by the Department of Homeland Security this month, first obtained by ABC News, said that Russian state media and proxy websites have sought to amplify criticisms of vote-by-mail to “undermine public trust in the electoral process.”

“We assess that Russian state media, proxies, and Russian-controlled social media trolls are likely to promote allegations of corruption, system failure and foreign malign interference to sow distrust in democratic institutions and election outcomes,” the bulletin says.

Clint Watts, who studies Russian disinformation at the Foreign Policy Research Institute, a nonpartisan think tank, said that Barr’s claims give Russian agents “the fuel to advance the conspiracies they want to amplify in America.”

State-owned media like Russia Today, Sputnik News and other news sites with Russian ties are regularly running headlines making unsupported claims about vote-by-mail, which often amplify arguments already being made inside the U.S., he said.

“It’s much better if it comes out of an American’s mouth,” he said.

Voting experts have said that counterfeiting ballots would not only be extremely difficult to execute but also easy for election officials to uncover.

A counterfeiter would need to know the exact ballot for each voter because ballot styles vary by jurisdiction with different state and local races and issues. Then the unique printing on the correct type of paper for scanners programmed to read that ballot would have to be reproduced, not to mention the bar codes and signature on envelopes used to identify each voter.

The faked ballots would also need to be matched with a registered voter who wasn’t going to vote either by mail or on Election Day because any instance of double-voting would lead to an investigation.

All of those measures mean it would be all but impossible to counterfeit enough mail-in ballots to sway a presidential election, said Jeff Ellington, president of Arizona-based Runbeck Election Services Inc., which provides printing, mailing and other election services.

“If I just printed 10,000 ballots and took them over to the county to try to get them to tabulate them, they’re going to have a sheriff on top me in a heartbeat,” he said.

Paul Gronke, director of the Early Voting Information Center at Reed College in Oregon, said the counterfeit ballot theory was from “the world of fantasy.”

Story by Ryan Teague Beckwith and Mark Niquette. Bloomberg writer Chris Strohm contributed to this report.