Washington: Some leading Democrats are increasingly anxious about Hillary Clinton's prospects of winning the party's presidential nomination, warning that Bernie Sanders' growing strength in early battleground states and strong fundraising point to a campaign that could last well into northern spring.
What seemed recently to be a race largely controlled by Mrs Clinton has turned into a neck-and-neck contest with voting set to begin in less than three weeks.
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Characterising Wall Street as an industry run on "greed, fraud, dishonesty and arrogance", Democratic presidential candidate Bernie Sanders pledges to break up the country's biggest financial firms within a year if elected president.
On Capitol Hill and in state party headquarters, some Democrats worry that a Sanders nomination could imperil candidates down the ballot in swing districts and states. Others are expressing a sense of deja vu from 2008, when Mrs Clinton's overwhelming edge cratered in the days before the Iowa caucuses.
Just as Barack Obama's stunning upset there helped assure Democrats in later states that a black man could win votes from whites and propelled him to victory in South Carolina and other places, so, too, could a Sanders victory on February 1 in Iowa and then February 9 in New Hampshire ease some doubts about the viability of a self-described "democratic socialist", some said.
"It's just like the weak spot for Barack Obama was his skin colour, but he got cured of that in Iowa," said South Carolina Democratic Representative James Clyburn, the party's leading African American in Congress.
"If [Senator Sanders] comes out of Iowa and New Hampshire with big victories – if it's close in both places, that's one thing – but if he comes out of there with big victories, hey, man, it could very well be a new day," Mr Clyburn added.
One Clinton ally on Capitol Hill said some in the party are starting to seriously consider what it would mean for Democrats nationally if Senator Sanders were to win.
"There's definitely an elevated concern expressed in the cloakroom and members-only elevators, and other places, about the impact of a Sanders nomination on congressional candidates," New York Democratic Representative Steve Israel, said.
Mr Israel, a former chairman of the Democrats' House campaign committee, said that a Sanders nomination "increases the level of anxiety that many of our candidates have in swing districts, where a Hillary Clinton nomination erases that anxiety".
Sensing the tightening race, some state party officials have gone out of their way to keep the peace with supporters of Senator Sanders, hoping to tap their energy and keep them activated for the general election campaign.
The re-evaluation of the Democratic primaries – which seemed destined for a Clinton coronation after she recovered from a damaging summertime slide amid controversy over her use of a private email system while secretary of state – comes as state and national surveys show her sliding fast once again.
A Des Moines Register survey of likely Iowa caucus voters released on Thursday showed a statistical dead heat, with Mrs Clinton at 42 per cent and Senator Sanders at 40. That marks a significant shift from a month ago when Mrs Clinton held a lead of 9 percentage points and saw her share of the vote at 48 per cent. In New Hampshire, Senator Sanders holds a commanding lead, 53 per cent to 39 per cent, according to a Monmouth University poll released this week.
Mrs Clinton and Senator Sanders have escalated their attacks on each other, with each claiming to be the strongest general election candidate.
The new dynamic will be on display in South Carolina this weekend, when the Democratic candidates attend a party dinner and then a fish fry hosted by Mr Clyburn ahead of their next debate on Sunday night. The pre-debate events, expected to draw hundreds of activists, will serve as a chance for Senator Sanders to prove that his campaign has an effective organisation beyond the first two states.
"We're really at the front end of the process for states beyond Iowa and New Hampshire," said Sanders adviser Tad Devine. "Part of the process is to convince people Bernie is a serious option, and doing well in early states helps with that."
Mrs Clinton's allies have said that they have always planned for a difficult primary season and that they expect their well-structured campaign to pay dividends when the race moves on to larger states with more diverse electorates than the two earliest states. They note that a recent trip to Oklahoma, part of the Super Tuesday bloc of 10 states on March 1, demonstrated their campaign's long view of the race.
"From day one we have told everyone who will listen this would be a dogfight," said Jerry Crawford, a long-time Mrs Clinton supporter in Iowa. "Hillary will continue to fight for every vote just as she has done since day one in Iowa, and I wouldn't trade places with any other campaign."
Whether or not he wins, Senator Sanders' rise has created challenges for party leaders by highlighting policy differences between the Democratic establishment and the party's support base.
Many of Senator Sanders' proposals – Medicare for all, free college and breaking up the big banks – go beyond congressional Democrats' agenda but are now embraced by an ascendant activist wing of the party.
Those policy prescriptions win support in primaries, but many Democratic elites fear how they will play in a general election. At the same time, Democratic leaders know they can't afford to alienate an energised party base.
Some recent surveys suggest that Senator Sanders is drawing support beyond the liberals and young voters who have been flocking to his rallies.
A Quinnipiac University poll early this month found Senator Sanders trailing Mrs Clinton by an insignificant 2 percentage points among moderate and conservative Democrats, a sharp shift from Mrs Clinton's 24 per centage-point lead among this group in December.
"Whatever the success that Senator Sanders, that Bernie Sanders has, I think it's important to recognise that his supporters are essential to our success in winning the White House," House Minority Leader Nancy Pelosi, of California, told reporters in the Capitol on Wednesday.
In the Senate, more than two-thirds of the Democratic caucus has endorsed Mrs Clinton. For now, the senators will remain calm, even if Mrs Clinton loses the first two states, according to a senior Democratic consultant working on Senate races.
However, full-fledged panic would set in if Mrs Clinton then loses the Nevada caucuses, wedged in between New Hampshire and South Carolina, the consultant said.
A Clinton defeat would complicate matters for one of the country's most vulnerable Democrats, Illinois Representative Cheri Bustos, who said on Thursday that much of her campaign strategy is based on energising female voters with the potential of a woman at the top of the ticket in Mrs Clinton and a woman running for Senate, with Democratic Illinois Representative Tammy Duckworth, the leading candidate. "There's a lot of excitement about having a woman at the top of the ticket," Ms Bustos said in an interview on Thursday, declining to directly critique Senator Sanders.
David Pepper, the Ohio Democratic Party chairman, said Mrs Clinton's infrastructure remains very strong, after her decisive victory over Mr Obama there eight years ago.
But, he said, the Sanders team has been on the move. Mr Pepper said he allowed Senator Sanders' supporters to use party headquarters to host a national "meet-up", and Mr Pepper met Senator Sanders after 6000 supporters attended a rally in Cleveland.
One of Senator Sanders' supporters recently announced a challenge to Ohio Representative James Renacci, a third-term Republican whose most recent re-election drew little competition.
"Our strategy of being intensely neutral and welcoming to all is paying off," Mr Pepper said.
Mr Pepper's approach differs from that of the Democratic National Committee, whose leadership has been feuding with the Sanders campaign over debate scheduling and other areas where Sanders allies say the party has shown favouritism to Mrs Clinton.
The central fight among Democrats could come down to how voters will perceive Senator Sanders, the wispy-haired 74-year-old former mayor of Burlington, Vermont, and whether they think his ideology could be a help or a hindrance.
"I'm deeply concerned that in November swing voters are not going to vote for a socialist," said Mr Israel, who is retiring.
Mr Clyburn, however, said he wasn't convinced Senator Sanders' ideology would be a drag, at least not in the primaries. He credited the senator for his consistent delivery over several decades of an agenda focused on erasing income inequality.
"I'm out there, and I know what Democrats are feeling," he said. "Democrats really feel strongly about this income-inequality business. That is a big, big issue."