Dropping out of a presidential race is a humbling experience.
Consider Scott Walker. The Wisconsin governor 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, including honoring Hilda the Holstein at the state's Cow of the Year presentation.
Over the next few weeks, several other Republican hopefuls with dwindling bank accounts and bottom-scraping poll numbers may be recapping the experience of Walker and Rick Perry, the former Texas governor who was the first candidate to quit this year's presidential race. Like them, they will have to weigh the risks to their reputations, finances and political futures of staying in the race versus getting out.
Either way, their egos are unlikely to survive intact. 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."
The next GOP debate, scheduled for Oct. 28, will put further pressure on the field. Unlike previous debates, which promised spots on a second stage for foundering candidates, the rules set by CNBC, the debate sponsor, could entirely leave out Sen. Lindsey Graham of South Carolina because he does not have 1% support in any of a selection of polls.
Those barely clinging to a spot on the second stage include George Pataki, the former governor of New York; Gov. Bobby Jindal of Louisiana and former Sen. Rick Santorum of Pennsylvania, who won the Iowa caucuses in 2012.
FOR THE RECORD
11:40 a.m.: An earlier version of this article stated that at least four Republican candidates were at risk of being left out of the next candidates debate. The criteria for the CNBC-sponsored debate allow a candidate to participate in the second-tier debate if he or she has 1% standing in at least one poll, not in an average of polls. Sen. Lindsey Graham is the one candidate currently at risk.
On the Democratic side, former Maryland Gov. Martin O'Malley may reconsider his prospects after failing to win the bump he was hoping for in last week's debate, falling below 1% in the two most recent polls.
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 Vermont Sen. Bernie Sanders. "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, 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.
Other factors also play a role in the decision on whether to stay or go. Some candidates may 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 may 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. Polls showed his popularity at home declining as he traveled the country, 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 be hoping 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 finishes 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 reelection in 2016 and may need to spend time and money at home to avoid losing his seat.
Former New Mexico 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.
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.
For more on Campaign 2016, follow @noahbierman