Hillary Clinton: Does anyone else stand a chance as Democratic presidential nominee?

Political furor over the emails of Hillary Clinton, who's all but anointed as Democratic nominee in the U.S. presidential race even though she hasn't thrown in her hat may be a gift to Republicans, but may also have provided a chance for other potential challengers from her own party.

Clinton, under fire for using a personal emailaccount to conduct government business while she wassecretary of state, and for having deletedthousandsof those emails, isexpected to announce hercandidacy this month, with some U.S. mediaspeculating that thelaunch of her second bid for the top job will come as early as this weekend.

• Hillary Clinton defends using private email account
• Hillary Clinton email excuses 'laughable,' says top freedom-of-information official
• Is Hillary Clinton too old to be president?
• Analysis:Why Hillary Clinton could bury the Republican presidential field

Althoughsome recent polls suggest the scandalmay be taking a toll on herapprovalratings,political experts say that unless something hugeemerges from the controversy, it's doubtful it will have much influence on Clinton's chances to become the party's nominee. Still, it hasprovided enough fodder to promptDemocrats,politicalpundits and Washington journalists to begin looking at other possible contenders.

Detractors of Clintonwillpoint to hercommanding poll lead in the 2008 primaries,before a young Illinois senator came along anddashed her presidential dreams.

Crushing the field

This time around, however, Clinton isnot just leading the pack of possible rivalsshe'scrushing it. Almost all polls have her ahead byroughly 40 points, with Vice-President JoeBidensecond by a big margin.

As well, none of the possible Democraticcontenders, so far, hasany kind of buzzcomparable to that of then candidate Barack Obama, whosekeynote speech atthe 2004 Democratic convention immediatelygenerated talk of a presidential bid in the near future.

Different names have been thrown around as possible contendersformer Virginia senatorJim Webb, Independent Vermont SenatorBernie Sanders, Secretary of StateJohn Kerryandeven Al Gore, whose spokespeoplequickly dismissed such notions.

But so far,the three individualsgiven the best chance to pose any kind oflegitimate challenge to Clinton are:

Elizabeth Warren, Massachusetts senator

An outspoken critic of Wall Street and incomeinequality, Warren has attracted a devoted following fromtheDemocratic Party's progressive wing, and is seen as theonly candidate whocould pose any kind of realchallenge to Clinton.

Despite many supportersbeggingher torun.her answer is always the same: No.

"I'm not running and I'm not going to run," sherecently told SavannahGuthrie, ofNBC's Todayshow, who tried every which way to get a different response from the senator.

"If she were to run, she would be Hillary's greatest threat, probably because a decent number of progressivegroups, more liberal organizations,are kind of on the 'draft Warren' team," said political analyst Geoffrey Skelley, associate editor atSabato'sCrystal Ball at theUniversity of VirginiaCenterfor Politics."They wouldlike to see Warren get into the race to push the issuesshe focuses on."

Still,Warren is no Obama, Skelley says, lacking his youth and a comparablemomentwhere she has captured the national attention, asObamadid at the 2004 convention.

If anything, just the threat of a Warren run could pushClintontofocus on thoseissues, out of fearofopening up further a divide in the party between thecentrists and progressives.

Clinton "really is in a position of incredible strengthand she doesn't want to screw that up by irritating theleft more than she already does," Skelley said.

MartinO'Malley, former Maryland governor

The guitar-playing populist former governor,who also appeals to the progressive flank of theDemocrats, has strongly hinted he will enter therace.

He has also taken a not-so-subtle shot at both RepublicanJeb Bush's probable run and Clinton's, saying toABC's This Week: "The presidency of the UnitedStates is not some crown to be passed betweentwo families."

But O'Malley'squest to take the nomination would be an uphill battle.He has little national name recognition and certainly wouldstruggle to amass thefundraising needed to mount a competitivecampaign against Clinton.

O'Malley is also coming off a relativelyrecent stunning political loss not his own, but his Democratic chosen successor to take over the governorship of his home state of Maryland. Not only was it a defeat, but a lossin an increasingly bluestate, as Kelley points out, whereDemocrats have won a higher percentage ofthe vote in the last elections than they have inCalifornia.

'Unless he's utterly deluded, his plan is not to go inthere and beat HillaryClinton. It's, 'I'm goingto be therein the event that something happens,'"said Tom Bevan,co-founder of the political websiteReal Clear Politics.

Joe Biden, U.S. vice-president

The inside scoop is that thevice-president will not launch a campaign unless Clinton bows out. Although he's well-liked and respectedamong many Democrats, his penchant for gaffes as well as his age(he's 72, five years older than Clinton), are factors against him.

"Biden has becomein manyrespectsa punchline, a punchline for members of his own party, a punchline certainly on the Republicanside. But it's alsoinmainstream culture.

Added Skelley: "I think it is telling that Clintonisoverwhelmingly ahead and that Biden,who is the sitting vice-president, would be so far behind and kind of almost out of sight,out ofmind for Democrats looking ahead to2016."