Hillary Clinton faces a range of high and unexpected hurdles to the Democratic nomination which, a year ago, was seen as hers virtually by monarchical right.

She has failed to get beyond the robust challenge from Sen. Bernie Sanders, a septuagenarian socialist whose political career has until now been more a curiosity than a powerful force.

Despite her efforts, Clinton has also failed to drum up enthusiasm for the idea of the historic election of America's first female president.

And she can't seem to shake the perception that, as a former first lady, former senator, former secretary of state and current establishment favorite, she is part of an elite against whom the base of both parties are rebelling this election cycle.

But perhaps the biggest challenge to her candidacy is yet to come. As the Federal Bureau of Investigation drills down on Clinton's handling of classified information on an insecure email network, the Democratic front-runner faces the possibility that she and her top aides could be indicted for compromising national security.

Despite her efforts, Hillary Clinton has failed to drum up enthusiasm for the idea of the historic election of America's first female president. (AP Photo)

Even if the odds are against her being charged, it's a possibility that has become less easily dismissed than it was last spring, when it was confined to hopeful whispers in Republican circles. Back then, even as news emerged that Clinton had handled sensitive government secrets, most people still thought she would cruise to the presidential nomination this summer.

But few people other than Clinton's own campaign hands now argue that the former secretary of state's legal situation is entirely secure. Two Obama administration agencies, the Justice Department and the State Department, are pursuing related lines of inquiry about her private email usage. Setting aside the handful of Republican-led congressional probes into her emails, experts say Clinton can no longer credibly make the case that concern about her handling of classified information falls strictly along party lines.

Which leads to certain questions. If accusations against Clinton lead to an indictment, what would follow? Could she continue to run for the White House? What would happen to her delegates? Would the Democrats allow themselves to be represented in the general election by Sanders, or would Vice President Joe Biden or some other champion step in to take her place?

Legal likelihood



While the FBI has been especially tight-lipped about the scope and focus of its investigation into Clinton's emails, the bureau recently acknowledged the probe has a "law enforcement" component, apparently repudiating Clinton's long-standing argument that it is nothing more than a routine "security review."

Michael Mukasey, former attorney general under President George W. Bush, said there's no such thing as an FBI "security review."

"That designation is unknown to anybody," Mukasey told the Washington Examiner. "The FBI doesn't conduct security reviews. They conduct investigations. They investigate possible crimes."

Mukasey said the few publicly available facts about the probe point to a thorough criminal investigation involving Clinton.

"If you've got 150 agents on a case, the FBI has acknowledged it's conducting an investigation, how much more real can you get?" he said. "It doesn't get much realer than that."

Clinton has characterized the lingering intrigue over her emails as a Republican attempt to weaken her prospects. Her national spokesman, Brian Fallon, has even attacked inspectors general appointed by President Obama when presented with details about their nonpartisan investigations into Clinton's private server.

But the Justice Department's involvement has proven increasingly difficult to write off as a partisan witch hunt.

Charles Lipson, a political science professor at the University of Chicago, said the legal issues underlying the email controversy are problematic regardless of how much Republicans have tried to exploit them for political gain.

Michael Mukasey, former attorney general under President George W. Bush, said there's no such thing as an FBI "security review." (AP Photo)

"It is political only because it is a serious legal matter in its own right," Lipson said. "This is not a fake issue. This is a real issue, and that doesn't mean that Republicans who blow it up aren't seeking political gain. They are, but they're doing it on the basis of something that is quite real."

The reality of the situation was thrown into sharp relief at the end of January, when the State Department announced its intention to withhold 22 emails, totaling 37 pages, because they contained "top secret" information. That decision brought the State Department in line with the intelligence community, which had argued since last July that some of the emails may contain information classified up to "top secret."

Since then, Clinton has had to stop saying the controversy is the result of a dispute between bureaucrats over what should be considered classified, as she and her staff have claimed for months.

Would the Democrats allow themselves to be represented in the general election by Vermont Sen. Bernie Sanders, or would Vice President Joe Biden or some other champion step in to take her place? (AP Photo)

Details about precisely how many emails are now being treated as top secret, as well as whether they were classified at the time they were written or only retroactively upgraded in light of subsequent developments, remain unknown. The FBI has a strict policy of refusing to comment on investigations that are still in progress.

But the basic public facts suggest the bureau already has solid grounds on which to recommend an indictment, said Andrew McCarthy, former assistant U.S. attorney in the southern district of New York.

"If the press reporting is to be believed, [the case] looks very strong," McCarthy said. "I say that because the statutes involving mishandling classified information are very prosecution-friendly, and they're obviously intended to be that way."

McCarthy points to the case of retired Gen. David Petraeus as an example. Petraeus pleaded guilty to a misdemeanor charge in April last year after sharing printed classified documents with a woman who was his biographer and mistress. Observers have drawn parallels between the Petraeus and Clinton cases, both of which involved the unauthorized disclosure of classified material.

"I was a critic of the Petraeus prosecution, because I thought he got a slap on the wrist," McCarthy said. "When Congress enacted these laws, the idea was to give the maximum amount of protection the criminal law could give to national defense secrets."

Observers have drawn parallels between the retired Gen. David Petraeus and Clinton cases, both of which involved the unauthorized disclosure of classified material. (AP Photo)

But a growing number of skeptics fear that, even if the FBI were to recommend an indictment, the Justice Department's leadership would decline prosecution of the likely Democratic nominee for political reasons.

"I'm very confident that the the FBI is going to do a thorough investigation and that if there's an airtight case to be made, they'll make it," McCarthy said. "What I'm not confident in is whether the Obama Justice Department will authorize the energetic use of a grand jury and, ultimately, an indictment."

"I know it's nominally Attorney General [Loretta] Lynch's call," he added. "But I think it's ultimately President Obama's call."

Mukasey dismissed concerns that Lynch would suppress charges against Clinton solely out of concern for her party's standard-bearer if the FBI presented her with a convincing case.

"This thing has reached critical mass, and I don't think that she would do that, given the likely outcome, which would be people resigning from the bureau and the Justice Department," he said. "So I don't see it."

Lynch told a House lawmaker that neither she nor other officials are receiving pressure to skew the investigation.

"And I'm also aware of no efforts to undermine our review or investigation into this matter at all," she said.

Attorney General Loretta Lynch told a House lawmaker that neither she nor other officials are receiving pressure to skew the investigation. (AP Photo)

Joseph DiGenova, a former U.S. attorney under President Ronald Reagan, told the Examiner in January that Lynch would have "no choice" but to indict Clinton if the FBI recommended an indictment. That recommendation would come in the form of a confidential memo, DiGenova said, but "the bureau will no doubt let it be known" that such a memo exists in order to increase the public pressure on Lynch to proceed with the case.

Most reports indicate FBI agents are looking into whether Clinton or her staff violated provisions of the Espionage Act that cover the treatment of sensitive information, an offense that can carry a sentence of up to 10 years in prison.

While a number of factors are at play in the unusual case of Clinton's emails, McCarthy said the former secretary of state could be looking at more than one felony charge.

"If it is as serious as it appears to be on its face ... this should be a multiple felony-count indictment and it should involve not only Mrs. Clinton, but whoever else in her circle at the State Department or wherever else knew that this activity was going on," he said.

The road ahead for Dems



If the Justice Department hits Clinton with criminal charges, she faces a difficult decision: withdraw her name from the Democratic primary, or continue to fight the perception of wrongdoing in the court of public opinion while hoping a court of law does not find her guilty.

"There's no legal reason why she'd have to drop out," Mukasey said. "The Constitution lists the qualifications for the presidency. And if you add anything else, it would be unconstitutional."

But most observers agree Clinton would struggle to remain in the race if a grand jury indicted her. At the very least, strategists say, the charges would invite another Democratic challenger into the primary and upend what still looks to be a relatively clear path to the nomination for Clinton.

Mark Jones, a political science fellow at Rice University's Baker Institute, said Clinton would most likely exit the race if indicted.

"If she withdraws, then effectively she can relieve all of her delegates from their pledge" to support her at the Democratic National Convention in July, Jones said.

A Democratic candidate needs 2,383 delegates to clinch his or her party's nomination. Two days after her victory in the Nevada caucus on Feb. 20, Clinton had already amassed 502 delegates to Sanders' 70, despite virtually tying him in Iowa and losing steeply to him in New Hampshire.

"At that point, we would see a brokered convention, where the most likely scenario would be that someone other than Sanders would be the Democratic nominee," Jones said. "It could be Elizabeth Warren, it could be Andrew Cuomo, Deval Patrick, Joe Biden."

Mark Jones, a political science fellow at Rice University's Baker Institute, floated Massachusetts Gov. Deval Patrick as a possible name to be considered in a brokered convention. (AP Photo)

Jones said Sanders' chances would not automatically improve in Clinton's absence, thanks to the Democratic Party's high number of superdelegates. Those are delegates not bound by the results of state primaries.

Superdelegates are already padding Clinton's delegate count. This year, 712 superdelegates will be free to back the politician of their choosing regardless of how their state votes.

"It would really be a return to the pre-modern era, back when the national conventions actually determined who the party's nominee was," Jones said of a situation in which Clinton leaves the race late in the primary.

"The delegates that are elected to support her would still have to support her on the first vote," he explained. "Superdelegates would not have to support her even if they had pledged to her."

A Democratic strategist who declined to be named in order to speak candidly guessed a Clinton withdrawal would benefit Biden more than Sanders because most superdelegates would flock to the vice president, not the Vermont senator.

"The superdelegates give Biden something to play with," the strategist explained.

Delegates at national conventions select their party's nominee using several rounds of ballots, if needed. But more than one round is not typically required, thanks to the primary elections and caucuses that precede the conventions.

"What is interesting is that we've been talking quite a bit about the prospect of a Republican brokered convention," Jones said. "But if Hillary Clinton is indicted, it's extremely likely that someone who has not been competing at all in the primary process would be the Democratic nominee."

New York Gov. Andrew Cuomo could also be a factor in a brokered convention. (AP Photo)

Jones said Clinton would have little choice but to leave the race if indicted because she would be unable to paint the charges as a partisan attack.

"If the evidence is so strong and so damaging that Loretta Lynch moves to indict, that says something," he said. "Because the default for the Obama administration in general and Loretta Lynch in particular would be not to indict. The last thing they want to do is indict Hillary Clinton. They would only do it if there was such strong evidence that there was no gray area or wiggle room whatsoever."

Lipson said he thinks the possibility of Clinton being indicted is "very real."

"Indeed, the only reason she wouldn't be indicted, I think, is if there was a political decision at the Department of Justice and the White House to prevent it, assuming that the FBI recommends such an indictment," Lipson said. "Of course, the Republicans are trying to make political hay out of this, and I think the American public is buying it, not because Hillary's avid supporters have changed, but because undecided voters now think she is fundamentally dishonest — not only because of the email scandal, but because the email scandal reminds them of so many other things that she's done."