Washington (CNN) Hillary Clinton and Donald Trump are better at beating themselves than each other.

They're not just the most unpopular presidential nominees in recent memory: In the epic drama of the 2016 election, they're also tarnished heroes who are perpetually humbled by their own self-defeating flaws.

The rivals, playing out their tragicomic duel on the grandest electoral stage, are like two Shakespearean protagonists falling prey to hubris, the excessive pride that can make a politician believe the rules that govern normal mortals do not apply to them.

Clinton's penchant for secrecy and distaste for disclosure have been the common theme in the deepest morasses of her long political career. Trump's overwhelming ego and self-obsession are at the root of the most damaging controversies that have raged around his wild presidential campaign.

And only one can survive. Within 10 days, the loser will see their hopes destroyed and partly have themselves to blame. The winner will go on to a presidency that at least in part will entail a battle against their fatal flaws.

Right now, it's Clinton who's on defense.

Her hopes of calmly cruising to an easy election win were shattered by FBI Director James Comey's sudden announcement Friday that the bureau is reviewing emails potentially related to Clinton's personal email server.

The new controversy centers on emails found on a device shared by Clinton's close aide Huma Abedin and her estranged husband, Anthony Weiner.

The Democratic nominee is responding by going on offense, accusing the FBI chief of interfering in the climax of a crucial political battle.

"It's pretty strange to put something like that out with such little information right before an election," Clinton told supporters in Daytona Beach, Florida, on Saturday.

Whether Clinton's complaint is valid or not, the case would never have been thrust into the frenzied final days of the presidential election were it not for her decision to use a private email server in the first place -- something she has admitted is a mistake.

The move was consistent with a character trait that has haunted Clinton throughout a quarter century in national politics. Critics argue that from the Whitewater real estate drama through the various pseudo scandals of the Clinton administration to her own campaign's missteps, she has made controversies worse by keeping things too close to the vest.

Neera Tanden, president of the liberal think tank Center for American Progress, asked the obvious question to Clinton's campaign chairman John Podesta.

"Why didn't they get this stuff out like 18 months ago? So crazy," Tanden wrote to Podesta in March 2015, according to hacked emails released by WikiLeaks.

Tanden then answered her own question: "They wanted to get away with it."

Clinton also attempted to escape scrutiny by the reporters for much of her campaign, going months without a press conference at one point.

Things changed in September, when the campaign finally brought reporters on Clinton's plane. Since then, she's regularly held informal gaggles and press conferences -- but even this shift, it seemed, happened grudgingly.

Clinton joked that her aide, Jennifer Palmieri, had forced her to the back of her plane to meet journalists.

"Good morning, everybody. I will come back later. Jen has convinced me I need to," Clinton said.

Clinton's allies defend her obsession with privacy by saying there's never been a political figure so unfairly victimized by her enemies -- by the "vast right-wing conspiracy" Clinton lambasted while she was first lady.

But justified or not, the tendency for opaqueness stings her again and again.

It was on display with her refusal to release speeches she gave to big Wall Street banks that became an issue with her Democratic rival Bernie Sanders. When the speeches were revealed in a WikiLeaks hack, their anodyne nature made everyone wonder what the fuss was about.

Clinton didn't disclose her diagnosis of pneumonia, but her fainting spell at a September 11 memorial event forced the campaign to come clean, renewing complaints that she simply doesn't want the public to know what is going on.

Trump can't resist a fight

Trump is also a master of self-immolation.

His gargantuan ego perpetually has him in hot water and leaves him volcanic at the smallest personal slight. It's a character glitch that's embroiled him in politically damaging spats with the parents of a fallen US Muslim solider, a Venezuelan beauty queen and an Indiana-born federal judge of Mexican heritage.

Trump's hubris was on display in the most damaging moment of his campaign, the release of a decade-old video showing him boasting about how his power and wealth meant he could make unwanted advances on women.

"When you're a star, they let you do it. You can do anything ... You can do anything," Trump told "Access Hollywood" host Billy Bush.

Most presidential candidates at least give lip service to the idea that their campaigns are an expression of the will of the American people. Not Trump.

Since he descended the golden escalator in Trump Tower last year to jump into the race, it's been all about Trump: his wealth, how smart he is, which famous people he knows, and -- until his fortunes took a dive -- his poll numbers. It's an approach that has allowed him to leverage his outsize personality and anti-establishment fervor to his advantage among adoring crowds. But the flip side has hurt him.

Last week, for instance, he trampled all his own closing argument in a speech at Gettysburg, Pennsylvania, by lashing out at women who accused him of sexual assault.

He's also ignored the advice of political aides like Paul Manafort and Kellyanne Conway, who helped revive his campaign but then saw the nominee veer off on his own direction, causing his political fortunes to plummet.

And he's also now gone months without a formal press conference.

While each candidate seems unable to prevent their own deficiencies from defining their campaigns, they've been uncannily good at exploiting their rival's flaws.

Clinton's obsessive secrecy, which has drawn her into repeated scandals and pseudo-scandals over quarter of a century on the national political stage is the building block on which Trump has built his "Crooked Hillary" caricature.

"This is the biggest political scandal since Watergate," Trump said on Saturday in Colorado, expanding his denunciation of her honesty and character.

Clinton, meanwhile, based her entire debate strategy around his fundamental flaw. She knew he'd be unable resist her provocations as she jabbed him over his bank balance, personality and treatment of women.

And she exploited his short fuse when his ego takes a hit, to bolster her case that he's unfit to be commander in chief.

"A man you can bait with a tweet is not a man we can trust with nuclear weapons," Clinton said during her Democratic convention address.