"You need to go when it's your time," said Douglas Gross, a Des Moines lawyer and GOP power broker. "The luster wore off. They pass the pie, and you'd better take your piece, because it's not coming around again. I don't sense a clamor for Christie."
His image has suffered some dents in the last 18 months, including the scandal over the 2013 lane closures on the George Washington Bridge in retribution against a Democratic mayor who would not endorse Christie's reelection. Two Christie allies were indicted, and one pleaded guilty to federal charges in the case. The governor has said he had no knowledge of the shutdown.
Also, New Jersey's economy grew just 0.4 percent in 2014, ranking 46th. The state's credit rating has been downgraded three times by each of the three ratings agencies under the Christie administration. And Atlantic City is falling apart.
Moreover, some on the GOP right mistrust Christie, considering him too moderate on social issues.
He has among the highest unfavorable ratings of the Republican contenders in most polls, a more reliable sign than horse-race numbers at this early stage of a candidate's potential standing.
Monmouth University's June 15 national poll, for instance, found Christie viewed favorably by 26 percent of likely Republican primary voters, and unfavorably by 43 percent - for a net of minus 17 percentage points. Fifty-five percent of Republicans in this month's Wall Street Journal/NBC News poll said they would never consider voting for Christie.
"There's a path for Christie, but it's a narrow one," said Patrick Murray, director of the Monmouth poll. "His high negatives and wide name recognition put a ceiling on his growth. He doesn't have much room for error."
And as for that blue-state electability, just 30 percent of New Jersey voters last week approved of Christie's job performance in a Fairleigh Dickinson University poll. And this is a governor who won reelection in a landslide, including carrying the Hispanic vote and gaining support from a majority of women - against a female opponent.
Christie's planning was based on his emerging as the establishment choice, a conservative but pragmatic governor who could appeal to moderates and be electable in November, strategists say. But he has been squeezed out. Others are competing to be that candidate, including governors with better economic records.
Former Florida Gov. Jeb Bush, Florida Sen. Marco Rubio, and Ohio Gov. John Kasich all have establishment appeal. And then there's Wisconsin Gov. Scott Walker, son of a Baptist preacher, who has governing credibility and support among evangelical Christian conservatives. Walker and Kasich have not yet declared.
Even for voters who back Christie, he's not the only offering of whatever it is they like about him. Christie took on public-employee unions, but Walker went bigger, stripping bargaining rights from those workers and pushing through right-to-work legislation.
Christie, who began his political career supporting abortion rights, now brags about vetoing state funding for Planned Parenthood. Yet Bush became a hero to pro-life groups as he fought to keep life support going for Terri Schiavo, a woman in a persistent vegetative state. And Walker is pushing a ban on all abortions in his state after 20 weeks' gestation.
"One obstacle Christie faces is, what's his argument for taking it to the next level?" said Kevin Madden, a GOP consultant who was a senior adviser to the party's 2012 nominee, Mitt Romney. "He doesn't have a defining issue, a rationale."
Since his popularity began tumbling after "Bridgegate," Christie has sold himself as an in-your-face truth-teller on issues such as pension reform and as a champion of detailed conservative domestic policies, such as a plan to cut Social Security and Medicare spending, as well as a muscular foreign policy.
Christie also can try to set himself apart with the force of his personality. He has charisma, but to some voters, there is a fine line between tough talk and bullying.
Perry Hamilton, a Lower Merion activist who saw Christie speak June 19 at a regional GOP conference in Philadelphia, illustrates the governor's predicament.
"We have at least six guys just like him," said Hamilton, 63. While he appreciates Christie's blunt manner, Hamilton said it's also a weakness. "Attitude: Sometimes I could do without that."
The crowded field could have an upside for Christie.
As long as nobody is pulling away from the rest, almost anything is possible, and it doesn't take much to win or place well in an early state. The thinking of his strategists: Why not stick around and see what happens? Maybe the governor will emerge from the rubble.
Another reason not to short Christie stock: He has a team of loyal donors who include Home Depot CEO Ken Langone and hedge-fund manager Stanley Druckenmiller. Both are expected to write big checks to the governor's superPAC America Leads, which can raise and spend unlimited amounts. Christie may not have Bush-scale dollars, but he'll be able to compete.
Christie's advisers say they're not writing off the other early states, but they want to plant their flag in New Hampshire, which holds the first primary and is traditionally friendly to moderate candidates. Christie has spent at least 19 days in the state this year, more than most, taking hundreds of questions from the public in the town-hall meetings that are his political trademark back in New Jersey.
It could be paying off. While he is bunched in the middle of the pack (and well behind celebrity Donald Trump), Christie has a better favorable-to-unfavorable ratio in New Hampshire than he does nationally. A Suffolk University poll last week found him viewed favorably by 44 percent of Republican primary voters in the state, and unfavorably by 42 percent - for a margin of plus-2 percentage points.
New Hampshire "is tailor-made for a Chris Christie-style retail campaign," pollster Murray said. "One on one, there's no better candidate in the field."
Right after making his announcement Tuesday at his old high school in Livingston, N.J., Christie is expected to head to the Granite State.
He's in a weaker position in the first-voting state, Iowa, which is scheduled to hold caucuses Feb. 1. A Des Moines Register/Bloomberg poll earlier this month found 58 percent of Iowa Republicans viewed Christie negatively, with 45 percent ruling out a vote for him.
Even if Christie performs well in New Hampshire, it's unclear where that might lead.
He'll immediately run into a GOP electorate in South Carolina that is dominated by white evangelical Protestants. A Winthrop University poll in April found that nearly 56 percent of evangelicals said they would not consider voting for Christie, one of the highest negative rankings among would-be candidates.
"He hasn't really been in consideration, part of the conversation," said Chip Felkel, a Republican strategist in Greenville, S.C., who worked on the campaigns of both Presidents Bush and is not aligned this time.
"He's viewed right now as a second-tier wannabe," Felkel said. "He's got to find some way to get momentum. The question is, does Christie have the ability to convince conservatives of his bona fides and not damage himself for the general election?"
After South Carolina comes Nevada, then a succession of Southern states on Super Tuesday. In early March, there's Florida, where Bush and Rubio are expected to dominate.
For his part, Christie professes not to sweat the polls. "It's not make-or-break," he told reporters in Iowa this month, "until people start voting."
Inquirer staff writer Maddie Hanna contributed to this article.