By Noah Bierman, Tribune Washington Bureau (TNS)

WASHINGTON — 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 and 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, the other hopefuls 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 increased 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 even that part of the event because they did not get 1 percent support in any poll.

In the end, George Pataki, the former governor of New York; Gov. Bobby Jindal of Louisiana; Sen. Lindsey Graham of South Carolina; and former Sen. Rick Santorum of Pennsylvania, who won the Iowa caucuses in 2012, all made the cut.

On the Democratic side, Jim Webb, a former senator from Virginia, dropped from the race on Tuesday. By Friday, Lincoln Chafee, a former Rhode Island governor and senator, also called it quits. Webb, who was polling at about 1 percent, said he may run as an independent.

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 percent in at least two recent national 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 the presidential campaign of 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, as well as Sen. Rand Paul of Kentucky, each spent more money in the third quarter of the year than they raised, according to recently filed campaign finance documents.

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 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 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 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.

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.

Photo: Bobby, it might be time to leave. DonkeyHotey/Flickr