Critics are blasting Hillary Clinton for claiming at Thursday night’s Democratic debate nothing will come of the FBI probe into her email practices and seizing on reports that other former officials received classified information on personal accounts -- saying she’s glossing over glaring differences between her case and theirs.

“The attempt to paint her predecessors in the State Department as equal offenders in mishandling classified material is an insult to what we now know to be the truth,” Rep. Darrell Issa, R-Calif., said in a statement Thursday, calling the argument an “everybody did it” defense.

Clinton pointed at the debate to emerging reports that former Secretary of State Colin Powell and the immediate staff of former Secretary of State Condoleezza Rice also received classified security information on their personal email accounts.

But the dozen emails reportedly connected to those cases represent a fraction of the more than 1,600 now-classified emails found on Clinton’s server. Further, no other secretary of state set up a private, “homebrew” server as she did.

“We’re talking apples and oranges here,” the National Journal’s Ron Fournier told Fox News.

“Official investigations have confirmed that Secretary Clinton’s unsecure server stored more than 1,000 emails containing classified information, including some classified at the very highest levels,” Issa said in his statement, put out earlier Thursday. “Her guarantee to the nation that the number was zero now seems more like desperation than news cycle spin.”

Clinton addressed the email scandal toward the end of the MSNBC-hosted debate in New Hampshire. She said she’s certain the matter will not derail her campaign.

“I have absolutely no concerns about it whatsoever,” Clinton assured, saying she's "100 percent confident" the FBI probe will fizzle.

In downplaying the matter, she was following comments by both President Obama and his chief spokesman. Last fall, Obama said in a TV interview he doesn’t think her practices posed a “national security problem.” And in late January, White House Press Secretary Josh Earnest, asked about the possibility of an indictment in the Clinton email case, said the case does not seem to be headed in that direction.

After that comment, a law enforcement source close to the Justice Department investigation pushed back, telling Fox News the probe was still ongoing and a decision had not been made.  

But all along, the Clinton campaign has dismissed the controversy as an interagency dispute over classification. And at the debate, she suggested investigators are going too far in their handling of the “absurd situation of retroactive classification.”

The details on Powell and Rice were included in a memo written by the State Department watchdog that was released Thursday.

IG Steve Linick said in the memo that two emails sent to Powell and 10 emails sent to Rice's staff contained classified national security information. Powell and Rice were the top diplomats under Republican President George W. Bush.

"None of the material was marked as classified, but the substance of the material and 'NODIS' (No Distribution) references in the body or subject lines of some of the documents suggested that the documents could be potentially sensitive," Linick wrote.

In a statement, Powell said the emails were from his executive assistant. He said that while the department now has said they are "confidential," which is a low level of classification, both messages were unclassified at the time and there was no reason not to forward them to his personal account.

Rep. Elijah Cummings, D-Md., top Democrat on the House oversight committee, pointed to those cases in saying he’s concerned Republicans are “disregarding the actions of Republican Secretaries of State” while scrutinizing Clinton.

He added: “The emails apparently had no classification markings, and it remains unclear whether the information in the emails was or should have been considered classified at the time it was sent.”

Still, the comments come less than a week after the State Department confirmed that, as it releases thousands of Clinton emails, it is withholding 22 emails containing information too “top secret” to release.

Pressed by Fox News, State Department spokesman John Kirby confirmed Thursday that the department accepts the 22 emails were “top secret” when they hit the server. Kirby also confirmed Clinton and top aides completed the required classification training, which covers the proper handling of classified material.

Fox News’ Catherine Herridge and Matthew Dean and The Associated Press contributed to this report.