Washington(CNN) Hillary Clinton's biggest challenge to a smooth launch of her 2016 campaign is a familiar one: Herself.
At the very least, the controversy over her exclusive use of personal -- instead of official -- email while Secretary of State threatens to further complicate her expected 2016 White House candidacy. The news is all the more challenging for Clinton after stinging criticism of foreign donations to her family's philanthropic foundation and her comments about her personal wealth.
But the email saga -- complete with echoes of scandals from the 1990s -- is perhaps the starkest reminder yet of the daunting risk Democrats are taking. The party is heading into a presidential campaign with a likely candidate who is a world figure with a proven domestic appeal -- see the 18 million primary votes she snagged in 2008 -- but who also has significant political vulnerabilities.
Clinton's stuttering last few months represent the kind of rough political patch that a strong Democratic primary opponent could exploit.
But Clinton's grip on the Democratic Party is so strong that no leading power broker is criticizing her, in the knowledge that the party lacks any other heavy-hitters for 2016. There is certainly no one with the star power or clout to capitalize on Clinton's troubles like Barack Obama did so successfully in 2008.
"I don't see there is any credible challenger," said one Democratic strategist, voicing the private belief of many in the party.
READ: Clinton asks State to release emails
While Sen. Elizabeth Warren is a rock star for the Democratic grass roots for her populist anti-Wall Street rhetoric, few in the party see her as a strong potential general election candidate. Vice President Joe Biden is biding his time and is beloved among Democrats, but would be an extreme long shot to beat Clinton. Another possible runner, former Maryland Gov. Martin O'Malley, polls lower than the margin of error in early surveys of the race.
It is testimony to the power of Hillary and Bill Clinton among Democrats that there are few prominent party figures willing to go on the record to voice doubts about the former secretary of state. It may also be a sign that key party figures realize that while Clinton may have flaws, she represents the only realistic chance of the party pulling off the rare feat of winning three presidential elections in a row.
But if there is no Democrat to take her down, Republicans believe that the email saga is another chance to severely weaken Clinton.
They say the question of Clinton's emails may reverberate deep into the campaign, because it fits a critical narrative that the Clinton way of politics is underhanded and often skirts the rules. Republican lawmakers, meanwhile, have the power to take the drama in unexpected directions as -- armed with subpoenas -- they plow through pages of turned over documents.
Though Clinton's defenders insist she did nothing "nefarious," and say she turned over 55,000 emails to the State Department last year, Republican National Committee spokesman Michael Short said Clinton set up a "homebrewed" server system to "skirt" federal transparency regulations for top officials.
Kevin Madden, a Republican strategist who worked for Mitt Romney's presidential campaigns, said the controversy would help the eventual GOP nominee build a case against Clinton.
"It may look like it is an transparency issue right now, but the bigger problem for the Clinton campaign is that this is going to morph into a character issue for Hillary Clinton," Madden said.
Republicans demands that more emails be turned over could also fuel other efforts by Clinton's foes on Capitol Hill, including those running the probe into the murder of U.S. ambassador Chris Stevens in Benghazi, Libya, while she was secretary of state.
READ: Stumbles fuel Clinton's Dem critics
All of this, combined with the lack of any clear sense as to the values and themes that are compelling a new Clinton campaign -- other than a historic quest to be the first woman president -- is contributing to a sense of uncertainty around her prospective White House effort.
"A crucial part of a campaign of a successful campaign roll out is momentum," said Madden. "This reminds the public of Clinton hangovers they had .... or every scandal that has been litigated. It is just drama after drama with them."
Privately, some Democrats are getting nervous that the kind of disarray that helped pull Clinton's 2008 campaign apart might be resurfacing -- even as others argue this is very much an arcane Beltway storm that is unlikely to trouble heartland voters.
Some are asking how a politician who has been as thoroughly investigated as Clinton, and who knew she might run for president again, would ever make a decision to sidestep official State Department email accounts.
And if it turns out the server Clinton set up to handle her email at her New York home was not sufficiently secure, the episode could take a much more serious turn and threaten her ability to argue that she's strong on national security.
Still, the email episode seems well down the list of blockbuster scandals the Clintons have survived -- so it's possible its impact could turn out to be peripheral to her political ambitions.
If so, it would mark the latest twist in an extraordinary tale of missteps and redemption that the Clintons have lived on repeat for much of their 40 years in politics.
Tracy Sefl, a senior advisor for the group "Ready for Hillary," detected no great concern about the email flap among elected officials at an "Emily's List" dinner headlined by Clinton this week.
"Each of them said with great conviction that their constituents could not care less about this," Sefl said. "Rather, their same constituents prefer to hear her ideas about issues that affect their lives. Yes, it's a familiar refrain, but that's because it remains true."
Both Clintons have long records of turning the heat of a political controversy away -- by showing that they are working hard for vulnerable middle class Americans who care little for Beltway scandal.
But Hillary Clinton is handicapped right now because she is not a declared candidate. She can't just get out on the stump and change the conversation or surround herself with loving crowds.
Some Democrats believe the last few days show the downside of Clinton's strategy not to jump into the race early, even though she lacks a serious primary opponent.
With this in mind, her late-night Tweet on Wednesday revealing that she had asked the State Department to reveal the content of her emails, only contributed to a feeling that she is dodging direct questions.
The White House, meanwhile, is in a tough spot as the row over Clinton emails becomes the latest point of tension in the long psychodrama between President Barack Obama and the Clintons.
It might not have been about Whitewater, Filegate, Travelgate or Monica Lewinsky but White House spokesman Josh Earnest got a small taste this week of what his 1990s predecessors like Mike McCurry faced when he was pummelled with questions about an alleged Clinton scandal.
Earnest's uncomfortable replies, in which he cited State Department procedures for the archiving of official email, appeared to be an attempt to insulate the White House from scandal while avoiding pitching the woman who is the best hope of preserving Obama's legacy deeper into the mire.
It's was an especially ironic moment, because Obama often implicitly invoked the Clinton wars to justify his push for a new kind of politics during his 2008 campaign.
A longtime Clinton ally admitted that there is an understanding in her camp now that the current flap could continue to fester.
"There is a sense among her allies that this story is complicated, and that it won't go away any time soon," the person said. "It won't matter in the end, given what a known quantity she already is across the political spectrum, but it will nonetheless linger."