Former House Speaker Newt Gingrich exulted in the FBI's disclosure that it would review emails that could be linked to a previously-closed investigation into Hillary Clinton's private server, predicting in an interview on Saturday that it could be "the final nail in the coffin" for the Democrat's campaign.

The ex-Georgia lawmaker compared the FBI revelation to the notorious scandal that rocked Richard Nixon after his landslide 1972 second-term victory, forcing him to resign less than two years after his election.

"Hillary is at least 50 times bigger a scandal than Watergate. It's not even close to being the same," said Gingrich. "If she were by some miracle to win - or anti-miracle, I should say - none of these people are going to accept that. None of these people are going to say, 'I guess she wasn't a crook, I guess she wasn't a liar.'"

He added: "A vote for Hillary is a vote for four years of constant investigation."

Gingrich and other prominent Republicans seized on the FBI's disclosure as a lifeline for Donald Trump's struggling campaign, which has trailed Clinton for weeks in both national polls and must-win battleground states. An Atlanta Journal-Constitution poll released last week showed the two in a statistical dead heat in Georgia, where a Democratic presidential nominee has not prevailed since 1992.

Clinton's campaign has scrambled to respond to the FBI inquest, which the New York Times and other outlets reported was gleaned from a computer that belonged to a Clinton top aide's ex-husband, disgraced former Rep. Anthony Weiner. At a Friday rally in Iowa, she demanded that FBI Director James Comey "release all the information that it has."

Top Republicans want the data dumped as well, including Gingrich, who led the effort to impeach Bill Clinton in his second term.

"The American people should not be hidden from information that could define this election," he said.

Gingrich predicted that there would be no honeymoon if Clinton won, saying her presidency would be clouded by questions of legitimacy before she takes office.

"On our side, she not only will have zero moral authority. She will have a negative moral authority," he said. "There will be a presumption that the country made a mistake and is putting in office somebody who is totally corrupt and totally dishonest."

Earlier, Gingrich told a crowd of dozens of Republicans in Sandy Springs that he spoke with Trump this morning about Georgia's 16 electoral votes.

"He said if you will carry Georgia, he will carry Florida," Gingrich told the crowd. "It's really important that we seal off Georgia. Let's get it done."