FBI Director James Comey testifies on Capitol Hill in Washington, March 1, 2016, before the House Judiciary Committee hearing on 'The Encryption Tightrope: Balancing Americans' Security and Privacy.'
FBI Director James Comey testifies on Capitol Hill in Washington, March 1, 2016, before the House Judiciary Committee hearing on 'The Encryption Tightrope: Balancing Americans' Security and Privacy.'

WASHINGTON - James Comey has been a tough U.S. prosecutor who faced down some of the most prominent defendants in the past quarter century and once dramatically helped set the rules for American surveillance of suspected terrorists. But now as director of the Federal Bureau of Investigation he has taken on his biggest role yet, injecting himself in an unprecedented way into the last days of the race for the U.S. presidency.

The 55-year-old Comey, a prominent figure in the Justice Department under Republican President George W. Bush and appointed FBI chief by Democratic President Barack Obama, has seemingly always exhibited an independent streak.

Now, little more than a week before the November 8 presidential election, Comey has announced that the FBI, the country's top law enforcement agency, is reopening its investigation into Democratic candidate Hillary Clinton's use of an unsecured, private email server while she was secretary of state from 2009 to 2013 and whether she mishandled classified national security material.

Democratic presidential candidate Hillary Clinton
Democratic presidential candidate Hillary Clinton speaks at a rally at NewBo City Market in Cedar Rapids, Iowa, Friday, Oct. 28, 2016.

No criminal charges

Comey had already declared in July that her handling of the classified documents found on her computer files was "extremely careless." But Comey said no criminal charges were warranted, a decision that angered Republicans looking to keep Clinton from becoming the country's 45th president and its first female commander in chief. Republican presidential candidate Donald Trump has often mocked Clinton as "Crooked Hillary" for her use of the private email server housed in her New York home, and Clinton has on numerous occasions called it a mistake, even as she says she did not knowingly send or receive classified material.

Republican presidential candidate Donald Trump spe
Republican presidential candidate Donald Trump speaks at a campaign rally at Open Door Christian Academy, Friday, Oct. 28, 2016, in Lisbon, Maine.

But the issue had to some degree taken a back seat in the campaign to the more recent disclosure of a 2005 tape in which Trump made lewd comments about women and boasted how he could grope them with impunity because of his celebrity status. He described the crude remarks as "locker room talk" and said he did not carry out his braggadocio, only to have a dozen women to say he had made unwanted advances on them over several decades, claims Trump called fabrications.

New developments

That all ended, however, when Comey, against advice from his superiors in the Justice Department, sent a letter to key congressional leaders saying investigators would again look at the Clinton case based on files found on a computer jointly used by a longtime Clinton aide, Huma Abedin, and her estranged husband, Anthony Weiner, a disgraced one-time congressman from New York. Comey said authorities found undisclosed files possibly related to Clinton while investigating Weiner for allegedly "sexting" with a 15-year-old girl.

Democratic presidential nominee Hillary Clinton, c
Democratic presidential nominee Hillary Clinton, center, speaks to aides, including Huma Abedin, left, aboard her campaign plane at Westchester County Airport in White Plains, N.Y., Oct. 22, 2016.

The U.S. Justice Department has a long-standing policy of not directly injecting itself into the country's politics, even as both Republicans and Democrats often ascribe political motivations for some of its decisions on what to investigate and whether to being charges against someone.

Comey told FBI staffers he felt obligated to let Congress know about reopening the Clinton email probe because he had repeatedly told lawmakers it had been completed. Comey said the significance of the new material found on the Abedin-Weiner computer as it relates to Clinton was not known and legal experts said the several thousand emails almost certainly would not be examined before Election Day. One report said authorities had not yet secured a search warrant to look at the material.

Clinton, with polls showing her ahead of Trump nationally and in key closely contested states that will determine the outcome of the election, attacked Comey's action and called on him to "explain everything right away, put it all out on the table," what details investigators are looking at.

Voters fill in their ballots at a crowded polling
Voters fill in their ballots at a crowded polling station on North Carolina's first day of early voting for the general elections, in Carrboro, North Carolina, Oct. 20, 2016.

"It's pretty strange to put something like that out with such little information right before an election," she told supporters in the Florida, a battleground state both Clinton and Trump see as crucial to their election chances.

"In fact, it's not just strange, it's unprecedented and it is deeply troubling because voters deserve to get full and complete facts," she said.

Trump, with new life in his campaign, denounced what he said was Clinton's "criminal and illegal conduct," as his supporters at a rally in the western state of Arizona shouted, "Lock her up!"

"This is the biggest political scandal since Watergate, and it's everybody's deepest hope that justice at last will be beautifully delivered," Trump said referring to the scandal that led to the resignation of President Richard Nixon in 1974.

Norman Ornstein, a political scientist with the American Enterprise Institute, described Comey's intervention in the election as "a very strange move."

"It violates the fundamental rule that the [FBI] has followed, which is that you don’t do anything or say anything that would influence an election within 60 days of the vote. Doing this 11 days before is very, very strange," Ornstein said.

"I don’t see Comey as a partisan in this case," Ornstein said. "But any sentient human being had to know that doing this 11 days before the election was going to hurt Clinton. By extension that was going to help Trump."

Ornstein suggested that Comey might have "wanted to build a stronger bond with some of his own FBI people" by releasing news of the reopened investigation.

"It’s also possible that he knew some of this people had leaked information to Republicans in Congress [about the new files], and if it got out that way, it would be damaging to him, either to hurt the FBI because it would look like a coverup, or that it would reflect badly on him. It’s fairly clear he was trying to mend fences with them. I look at that and look at what might be the most consequential election in our lifetimes, and if your motivations are largely personal, and maybe a little bit institutional, if he was trying to protect the FBI, the irony is that he‘s damaged the institution."

Political historian Allan Lichtman at American University in Washington said Comey "has no business doing this."

"It’s also quite remarkable that the director of the FBI won’t even say if he’s investigating ties between the Trump campaign and the Russians and yet here he is, right from the start, giving blow by blow, detailed accounting of what’s going on in the Clinton email investigation," Lichtman said. "The double standard here is just glaring."

In a long legal career, Comey has prosecuted members of the Gambino crime family, terrorists accused of carrying out the 1996 Khobar Towers bombing in Saudi Arabia, corporate executives involved in financial corruption and popular lifestyle television host Martha Stewart in a securities fraud case, often winning convictions and sending the accused to prison for lengthy terms.

His sense of independence in the face of countervailing advice from his superiors has been a hallmark of his years on the front stage of U.S. law enforcement.

In 2004, in the Bush administration, he was the acting attorney general at a time when his boss, John Ashcroft, was hospitalized. White House officials sought his approval on the legality of key aspects of the country's National Security Agency surveillance of suspected terrorists, but Comey objected.

FILE the National Security Administration (NSA) c
FILE - The National Security Agency in Fort Meade, Maryland, says classified information was stolen by a former NSA contractor and included the names of covert intelligence officers.

When the White House officials went directly to the hospital to try to get the ailing Ashcroft to sign off on the provisions of the surveillance, Comey went to the hospital room himself and rebuffed the presidential aides.

Comey withdrew his threat to resign over the standoff, and after Bush heard his objections, changes were made in the surveillance program.

Marissa Melton contributed to this report.