Richard W. Painter described Attorney General William Barr as the "most dangerous" in United States history, citing what he described as religious zealotry.
Eric Holder, who was attorney general in the Obama administration, attacked William Barr in an op-ed for "running political interference for an increasingly lawless president."
"This is really a collision between order and rule of law," former NATO Supreme Allied Commander James Stavridis said.
The attorney general has continued to defend President Donald Trump's attacks on the FBI even after many of his conspiracy theories were debunked.
"The report's headline findings are that the investigation was properly initiated based on a sound factual basis," attorney Donald Ayer said.
"We know Barr will do anything for Donald Trump," Joe Scarborough said, describing William Barr as the president's "hack."
Frank Figliuzzi also said the attorney general had a "consistent ability to ignore facts" on MSNBC Monday night.
Attorney General William Barr said he was willing to go to the U.S. Supreme Court to ensure federal executions will restart despite a temporary block by a U.S. district judge, according to the Associated Press.
The attorney general gave his most pointed attack on Democrats to date, saying Trump's opponents are trying to sabotage his administration.
William Barr is "the president's hand – not the representative of the American people," Representative Adam Schiff warned.
Attorney General William Barr reported to have opened investigation into special counsel's 2016 election review.
"Because we have not had a diverse voice at the top of the ticket in leadership in the state of Mississippi, some voices are not heard," Jennifer Riley Collins told Newsweek.
"This is what we see in mob cases. It makes no sense," the Morning Joe host said.
"These facts that he laid out are so substantially similar to the matured allegations against Bill Clinton and Richard Nixon, it's clear where he was going," Andrew Napolitano explained.
The veteran journalist said the situation challenged "whether our institutions are able to function in this country to deal with a president of the United States who is unique in our history, who has nothing but contempt for Democratic traditions and the rule of law."
"It seems that individuals in the Justice Department at the highest levels who seem to state the facts and the law as they exist seem to not do well," said former Deputy Assistant Attorney General Elliot Williams.
"Are they looking for a redo because they hated seeing the strong NO COLLUSION conclusion? There was no crime," the president insisted on Twitter.
"We will make one more good faith attempt to negotiate and to get access to the [Mueller] report, and if we don't get that, we will proceed to hold the attorney general in contempt," House Judiciary Committee Chairman Jerrold Nadler threatened.
A link to sign a petition apparently led to another "step" in the process to contribute to the senator's 2020 presidential campaign.
Former judge Andrew Napolitano said that the attorney general "was splitting hairs" in trying to explain his previous testimony to Congress.
Omarosa Manigault Newman told MSNBC that she wouldn't be surprised if she were subpoenaed by Congress.
House Oversight Committee Chairman Elijah Cummings said Bill Clinton's behavior "pales in comparison" to Donald Trump's alleged efforts to obstruct justice.
"Sanders told this Office [of the special counsel] that her reference to hearing from 'countless members of the FBI' was a 'slip of the tongue,'" investigators wrote in the Mueller report.
"I suspect that Democrats' heads on Capitol Hill were exploding," Fox News' Chris Wallace said following Attorney General William Barr's press conference on the Mueller report.
Forty-eight percent of Hillary Clinton voters said they had an unfavorable view of Attorney General William Barr, while 9 percent of Trump voters had an unfavorable opinion of Barr.
"This is not an issue for us, it is not a thing that interests us or causes us concern," Kremlin spokesman Dmitry Peskov said.
"Domestic spying during a presidential campaign did happen and we have a right to know who participated in it, who authorized it and what their motives were," Carlson said after listing instances where he believes the FBI spied on Trump's presidential campaign.