Washington (CNN) Americans have not heard the last of Hillary Clinton's emails.

Republicans pumped FBI Director James Comey Thursday for fresh evidence to prolong the politically damaging saga during a Capitol Hill hearing that ignited partisan anger over his decision not to seek charges against the presumptive Democratic presidential nominee.

GOP lawmakers vented frustration that Clinton escaped criminal action over her use of a private email server while serving as secretary of state while Democrats blasted the hearing as no more than a tax-payer funded witch-hunt.

The four-and-a-half hour hearing, however, appeared to eke out several new seams for Republicans to pursue. House Oversight and Government Reform Committee Chairman Jason Chaffetz said he would ask the FBI to probe whether Clinton lied to Congress over her email arrangements. The agency, Comey said, did not investigate Clinton's testimony before the House Benghazi panel last year because Congress had not asked it to.

"I think when you come to Congress you need to provide truthful testimony and if you don't provide truthful testimony there should be a consequence," Chaffetz told reporters after the hearing. "I thought the FBI was looking at this, but evidently, they're not. They weren't looking at it."

Comey also testified that while people copied on Clinton emails had security clearances, some contractors who maintained the server and lawyers who examined her emails did not.

Republicans tried to build an impression that Clinton repeatedly misled the American public over her motives and use of the private server system -- something Republicans hope will highlight questions about her trustworthiness.

JUST WATCHED FBI: Clinton not sophisticated with classified info Replay More Videos ... MUST WATCH FBI: Clinton not sophisticated with classified info 01:59

South Carolina Rep. Trey Gowdy asked Comey a series of questions rooted in the former secretary of state's statements on the issue.

"Secretary Clinton said there was nothing marked classified on her emails, either sent or received. Was that true?" Gowdy asked.

"That's not true," Comey replied.

"Secretary Clinton said, 'I did not e-mail any classified material to anyone on my e-mail, there is no classified material.' Was that true?" Gowdy went on.

"There was classified material emailed," Comey replied.

As the politicians played for the cameras, Comey sat unruffled, vigorously defending the FBI probe and explaining why the presumptive Democratic nominee escaped indictment even though he had fired off a withering critique of her handling of classified information on Tuesday.

"I think she was extremely careless. I think she was negligent -- that I could establish," Comey told the House Oversight and Government Reform panel. "What we can't establish is that she acted with the necessary criminal intent."

While Comey was the witness, Clinton was clearly the target of the hearing as Republicans seek to keep the controversy over her email setup alive to highlight her most glaring vulnerability heading into November's election, questions about her character and honesty.

"There is no consequence, director -- there is no consequence," Chaffetz said, demanding to know why Clinton and her aides do not appear to be paying a price over the long-running controversy.

"We are mystified and confused by the fact pattern that you laid out and the conclusions that you reached," said Chaffetz, adding that "the Average Joe" would have been led off in handcuffs had they done what Clinton did.

Comey also testified that there were three emails found on Clinton's servers bearing the letter "C" which denotes they were classified, in apparent contradiction of the former secretary of state's statements.

But he said it was not clear whether Clinton knew that such a designation denoted classified material, saying "the secretary may not have been as sophisticated as people assume" when it comes to such issues.

But Comey testified that Clinton did not lie to the FBI during their year long probe which culminated with her interview with bureau agents on Saturday and explained that the agency did not want to "put people in jail unless we can prove they knew they were doing something they shouldn't do."

JUST WATCHED Donald Trump on Clinton emails: Lies, lies, lies Replay More Videos ... MUST WATCH Donald Trump on Clinton emails: Lies, lies, lies 01:37

And, following Attorney General Loretta Lynch's announcement Wednesday that she would accept the FBI's findings and close the case, Comey explained the legal distinction that underpinned his decision not to seek charges.

"My conclusion was and remains that no reasonable prosecutor would bring ... the second case in 100 years for gross negligence," Comey said.

He explained that under relevant statutes, prosecutors would have to prove Clinton clearly knew she was breaking the law to win a case.

"Should have known, must have known, had to know, does not get you there," he said.

The Clinton campaign argued after the hearing that it had been a mistake for Republicans to put Comey, a former prosecutor who served in President George W. Bush's Republican administration, on the spot.

"If you were a House Republican sitting on the panel today, you probably felt like that hearing backfired," Clinton campaign spokesman Brian Fallon said on CNN's "The Situation Room with Wolf Blitzer," arguing that the GOP had tried to use the hearing to create a "drip, drip" of coverage that would keep the issue in the news.

Fallon also said that all of the lawyers who sorted Clinton's emails did in fact have security clearances, contradicting Comey's comments. And asked whether Clinton had lied to Congress, Fallon replied: "Of course not."

Committee Democrats spent the hearing portraying the whole affair as yet another attempt by Republicans -- following the House Select Committee on Benghazi -- to use the mechanics of government to wound their presidential nominee.

"In their eyes, you had one job -- and one job only -- to prosecute Hillary Clinton," the Committee's ranking Democrat, Rep. Elijah Cummings, told Comey. "But you refused, so now you are being summoned here to answer for your alleged transgressions."

Hours after Comey's hearing, the State Department announced it had reopened its probe into Clinton's email use, an investigation that will focus on whether current employees involved in handling or sending and receiving Clinton's emails should get disciplinary action. The department had suspended its probe while it was waiting for the Justice Department to complete its criminal investigation.

As the drama unfolded in a House hearing room, Republican presumptive presidential nominee Donald Trump was elsewhere on Capitol Hill, meeting GOP House and Senate lawmakers.

Clinton was also in Washington Thursday, huddling with senior advisers at her home just off Embassy Row.

Republicans are trying other avenues to keep the email controversy that has clouded her presidential campaign for months, alive.

House Speaker Paul Ryan, for instance, asked the Office of the Director of National Intelligence to block access to classified briefings for Clinton for the rest of the campaign.

Trump, Rubio fundraise off Comey's testimony

Trump sent out a fundraising email during the hearing, complaining that the FBI had let Clinton "off the hook."

"We know the FBI refused to hold Lying Crooked Hillary accountable. But working together, we can hold her feet to the fire," Trump wrote.

Florida Sen. Marco Rubio sent out a similar solicitation for his re-election bid, arguing that the email saga proved Clinton was unfit to serve as President.

"If Hillary becomes president, this will not be the last scandal the American people will endure," Rubio warned.