With less than 100 days to go before the Iowa caucuses, presidential hopefuls with dwindling bank accounts and bottom-scraping poll numbers are beginning to weigh the risks of staying in the race versus getting out.
Two candidates on the Democratic side, former Sen. Jim Webb of Virginia and former Rhode Island Gov. Lincoln Chafee, called it quits last week. Their decisions came shortly after Vice President Joe Biden — who has long harbored a desire for the presidency, and who was polling in third place despite not being a candidate — announced he did not believe there was enough time left in the calendar to mount a credible campaign.
On the Republican side, former Texas Gov. Rick Perry and Wisconsin Gov. Scott Walker have already left the race, and more winnowing of the crowded GOP field is possible as voters in early nominating states begin to sharpen their focus on the contest.
Candidates that have failed to catch fire so far must decide whether they have a realistic shot at momentum in coming months, or whether staying put could pose a risk to their reputations, personal finances and political futures.
History shows candidates are likely to push against the odds for as long as they can resist sober political facts.
"You have to rely on candidates to do their own self-assessment," said Eric Fehrnstrom, a political strategist for Mitt Romney's two presidential campaigns who is neutral in the 2016 race. "And the problem with that is honest introspection is in short supply in politics."
Former Maryland Gov. Martin O'Malley has faced renewed questions about the long-term sustainability of his campaign after he failed to win the bump he was hoping for in the first Democratic debate this month and saw support fall below 1 percent in at least two recent national polls.
O'Malley, who reported less than $1 million in the bank at the end of the third quarter, has remained optimistic. He said he is confident he'll have the money needed to compete.
"We've seen a big uptick in our fundraising, a big uptick in interest since the debate," O'Malley said recently in New Hampshire. "I feel very good about where we stand right now. ... It couldn't have come at a better time."
For politicians who have spent much of their career thinking about the possibility of a run for the White House, the decision can be a humbling experience.
Consider Walker. He spent August and September outlining plans to remake the nation's economy and pontificating on the global threat of Russian aggression.
Then his campaign crashed. A week later, he was back at his day job, and honoring Hilda the Holstein at the state's Cow of the Year presentation.
Over the next few weeks, several other Republican hopefuls may follow the experience of Walker and Perry, who was the first candidate to quit this year's presidential race.
The next GOP debate, scheduled for Oct. 28, will put further pressure on the field. As in previous debates, the candidates at the bottom of the pack will appear in a separate early session. For a time, some seemed at risk of not making the cut even for that event.
In the end, former New York Gov. George Pataki, Louisiana Gov. Bobby Jindal, Sen. Lindsey Graham of South Carolina and former Sen. Rick Santorum of Pennsylvania — who won the Iowa caucuses in 2012 — all made it in.
Money, and the risk of incurring personal debt, is the driving factor for most candidates who opt out.
"If they run up $4 million or $5 million debt, in hard money, that's going to be hanging around their necks for a long time," said Tad Devine, a longtime Democratic strategist who is advising Sen. Bernie Sanders of Vermont. "You're talking multimillion-dollar decisions every week."
The nation is littered with former presidential candidates whose careers were weighed down by the burden of campaign debts, Devine said.
The four candidates at the bottom of the GOP pile — Pataki, Jindal, Graham and Santorum — as well as Sen. Rand Paul of Kentucky, each spent more money in the third quarter of the year than they raised, according to campaign finance documents filed last week.
Even Republican Jeb Bush, once considered a favorite for the nomination, was reportedly forced on Friday to order across-the-board pay cuts in the face of dwindling funds.
Other factors also play a role in the decision on whether to stay or go. Some candidates might prolong time in the campaign to advance a single issue, enhance a career in television, or set themselves up for a job in the next administration. They might time their withdrawal to raise the leverage of their endorsement or preserve their standing at home.
Walker, who withdrew late last month, had entered what Fehrnstrom and other consultants call a "doom loop."
His poor performance in debates and on the campaign trail led to lower poll numbers, which made it harder to raise money from disillusioned donors. Without money, a candidate cannot afford the ads or campaign apparatus needed to push poll numbers back up and end the cycle. Walker left the race owing more than $1 million.
In addition to running out of money, Walker, 47, had to worry about his political future. As he traveled the country, polls showed his popularity at home declining and his clout within the state legislature at risk.
Walker implored other candidates to drop out with him in hopes that establishment Republicans could unite behind one or two candidates to push back against Donald Trump, who is leading most polls. So far, his former rivals have resisted, and the field remains splintered.
Some candidates, even though low in the polls, may hope someone else who competes for the same type of voters will drop out first. Santorum and former Arkansas Gov. Mike Huckabee, for example, both play to religious conservatives. Paul and Sen. Ted Cruz of Texas both have appeal for tea party supporters.
Graham is typical of a type of candidate who often stays in longer than his poll numbers or fundraising would justify. He is a message candidate, eager to push his party toward embracing a muscular foreign policy, and is not spending much money on ads, campaign staff or chartered air travel. By raising his profile on the campaign trail, he may improve his odds of serving as Defense secretary in a Republican administration or increase his voice within the Senate.
Yet even if the senator can stay in the race through the first two nominating contests next year — in Iowa and New Hampshire — many are betting he will withdraw before the third contest, in his home state of South Carolina. He would face embarrassment if he finished at the bottom of the pack there, and his endorsement may hold slightly more value if he withdraws shortly before the South Carolina voting.
Paul faces a related problem. Once considered a potent contender, the face of his party's libertarian wing has fared poorly. But unlike Graham, he is up for re-election in 2016 and may need to spend time and money at home to avoid losing his Senate seat.
New Mexico's former Gov. Bill Richardson said the lifeline provided to candidates by super PACs can distort the normal deliberating process and may keep several underperforming candidates in the race longer.
"Your heart tells you stay in, you'll do better," he said. "Your gut tells you you'll be hopelessly in debt, it's not the responsible thing to do."
Richardson said he knew long before he dropped out of the 2008 Democratic primary that he would have little chance against Barack Obama.
After Obama mesmerized the crowd at a candidate forum in Iowa, Richardson told his wife, Barbara, "I think this race is over," he recalled.
Still, Richardson stayed in until the money ran out just after the New Hampshire primary, where he finished a distant fourth place.
And even then, he was reluctant, telling supporters in his concession speech that better days were ahead in Nevada, where his Latino heritage might prove a bigger asset. But on the plane home from Manchester, N.H., his closest friend, his daughter, and his top two campaign strategists delivered the hard truth. He was in debt and would need another $2 million to compete in Nevada.
"My brain trust said to me, 'Guv, we can't go on,'" he recalled. "And my wife was there, and she said, 'I don't want to go into debt.'"
The next day, he withdrew from the race.