SALT LAKE CITY — Sen. Mike Lee accused Facebook and Twitter of being biased against Republicans and conservatives during the 2020 election, including tagging one of his own posts about alleged voter fraud.

The Utah Republican sharply questioned Facebook CEO Mark Zuckerberg and Twitter CEO Jack Dorsey about their promise to take a politically neutral approach to election content moderation at a Senate Judiciary Committee hearing Tuesday.

Lee said he found it “a little disturbing” that Facebook tagged one of his posts about the presidential race with “voter fraud, which is historically rare, has not affected any outcome in this election” and that mail-in balloting was “conducted in accordance with state voting rules.”

“The tag to me sounds a whole lot more like state-run media announcing the party line rather than a neutral company, as it purports to be, running an open online forum,” he said. “This kind of editorializing insulates people from the truth and it insinuates that anyone concerned about voter fraud must be crazy.”

President Donald Trump continues to wage war over the election results that left him well behind former Vice President Joe Biden in both the popular and Electoral College vote. The president has called the election “rigged” and “stolen” and has claimed victory more than once since Nov. 3.

Sen. Dianne Feinstein, D-Calif., asked Zuckerberg if he was concerned that Trump’s claims about the election might incite violence.

“I’m very worried about this, especially any misinformation or content that could incite violence and during such a volatile period like this,” he said, adding one Facebook’s top priorities is making sure people don’t use it to organize violence or civil unrest.

Lee said concerns about election irregularities might be out of the mainstream in Palo Alto, but they’re not out of the mainstream for the rest of America.

Facebook, bias and the battle over conservative and liberal content on social media

“I hope this kind of manipulation wasn’t intentional. But it’s getting harder and harder for me to accept the premise that it could be anything but intentional,” he said.

Lee accused Facebook of violating federal trade laws prohibiting businesses from engaging in unfair or deceptive practices when it comes to its pledge of neutrality.

“However, as we heard today and will continue to hear into the foreseeable future, there are instances in which your platforms are taking a very distinctively partisan approach and not a neutral one to election-related content moderation,” he said.

Zuckerberg said as Facebook strives to handle millions or billions of pieces of content a day as well as possible but does make mistakes.

Lee also asked Zuckerberg about tagging political ads for “missing context.” He said political ads and ads in general always lack context. He questioned whether Facebook had ever applied that label to a Democratic ad.

Zuckerberg said he was not familiar with that standard.

Facebook has resoundingly heard from users that they don’t want to see misinformation and believe it is a problem, he said. But they also don’t want it to be the arbiter of what is true and false.

“For what it’s worth, I strongly agree with that and I do not think it is the right thing for us to assume that role,” Zuckerberg said.

Both Zuckerberg and Dorsey acknowledged their platforms had made errors but also took steps to correct them.

Lee demanded to know why Twitter suspended the account of Mark Morgan, U.S. Customs and Border Patrol commissioner, for a tweet about the success of the southern border wall days before the election.

Dorsey said Twitter evaluated the tweet and found that Twitter was wrong. He said the mistake was due to “heightened awareness around government accounts during this time.”

“I understand that mistakes happen,” Lee said. “What we’re going to see today is that mistakes happen a whole lot more, almost entirely on one side of the political aisle rather than the other.”