It's hard to say goodbye in presidential politics.
Newt Gingrich's campaign pinned his future on two Deep South victories, which never materialized. Yet the former House speaker is pressing on despite a path to victory that seems more improbable by the day.
The 2012 GOP race has seen such stand-tough moments before. Tim Pawlenty, Michele Bachmann, Herman Cain, Jon Huntsman and Rick Perry all promised to soldier on when things looked bleak. Eventually they bowed out _ some meekly _ after realizing they couldn't overcome increasingly long odds.
The decision to make a run at America's highest office is difficult, given a presidential campaign's grueling hours, grinding travel, constant exposure and lost privacy. Getting out can be just as tough, a very public admission of failure.
"Sometimes you're in the bubble so long and working so hard that you just can't see the off switch," said Keith Nahigian, who managed Bachmann's presidential campaign and worked on seven others before that.
Timing an exit can make a difference.
After a graceful 2008 departure, Mike Huckabee found post-campaign life lucrative, through book sales and a cable TV show. That year, Mitt Romney didn't overstay his welcome either and left himself in a commanding position for a shot in 2012.
At 68, Gingrich is in the twilight of his career. Since leaving Congress in 1998, he has cultivated politically connected businesses that he may need to consider as he weighs his campaign's future.
Speaking to a GOP dinner Wednesday night in Illinois, Gingrich defiantly proclaimed that no other candidates for the Republican nomination offer policy solutions as bold as his on such issues as energy development and government restructuring.
"That's why I'm still running. The vacuum is so huge," Gingrich said, calling his effort "the politics of big ideas."
"The news media can't cover it," he said, "and, candidly, my opponents can't comprehend it."
Some political observers suspect that Gingrich is still so raw over the onslaught of negative ads by Romney and his allies that he's sticking around to make the former Massachusetts governor's campaign for the nomination that much tougher. Others think Gingrich might be able to leverage his withdrawal with former Pennsylvania Sen. Rick Santorum, who stands to benefit the most if Gingrich were to leave the race.
Gingrich and Texas Rep. Ron Paul, who is winless so far, talk of sticking around until the Republican convention in Tampa, Fla., in August even if they get there on fumes and with no real chance of securing the nomination. Whether both actually trudge that far is anyone's guess.
Bachmann's dismal finish in Iowa's leadoff caucuses forced her exit, but the Minnesota congresswoman slept on the decision and waited just before a flight to South Carolina to bow out.
Iowa also sank Pawlenty, although the former Minnesota governor abandoned his years-in-the-making campaign after a GOP test vote the summer before the actual caucuses. Months later, he expressed regret about leaving so soon.
Perry's crippling blow came early as well. The Texas governor powered down his campaign after a lackluster Iowa caucus showing but reversed course and headed to South Carolina for a last stand. He called it quits for good just days before South Carolina's primary and endorsed Gingrich.
Huntsman, the former Utah governor, trekked south after New Hampshire's primary, but he too was gone before the next contest, throwing his support to Romney. Cain vowed to remain a candidate even though he was facing allegations of sexual misconduct, then announced during the opening of his Georgia campaign headquarters that the campaign was all but over.
The field has been static since. Romney has traded victories with Santorum and, to a far lesser extent, Gingrich. None of them is remotely close to the 1,144 delegates needed for nomination.
If there is no nominee-in-waiting, both Paul and Gingrich could be power players if they have delegates under their control.
A few prominent conservatives are publicly pressuring Gingrich to drop out to unify social conservatives, who haven't been enamored of Romney. Richard Viguerie, a longtime GOP fundraiser now aligned with Santorum, stepped up his call in a prepared statement issued Wednesday that used charm with his fellow Republican.
"Far from asking Newt to withdraw from the fight to nominate a movement conservative for president, I am asking that he take a leading role _ perhaps the pivotal role _ in that battle, by throwing the weight of his formidable intellect and political skills behind Rick Santorum," Viguerie said. "I urge my old friend Newt to unify the conservative movement, not by quitting the fight, but by joining Rick Santorum to win it."