New Jersey Gov. Chris Christie‘s decision not to run for president almost certainly means that the 2012 Republican presidential field is set, news that some donors and party activists may greet grimly.

New Jersey Governor Chris Christie won’t run for president in 2012. (AP Photo/Mark Lennihan)

That Christie took a pass on the race is not all that surprising since he had been resolute for months that he was not interested in running before a brief — and recent — re-consideration.

But, the clamor — particularly among the donor community if not among rank and file activists — for a Christie candidacy speaks to the ongoing discontent with the Republican field of candidates.

Since the start of the Republican race, former Massachusetts governor Mitt Romney has been regarded as the frontrunner — if a somewhat weak one.

Conservatives — particularly those aligned with the tea party movement — have spent much of the year looking for an alternative to Romney, a nomadic journey that has led them to latch on to reality TV star Donald Trump, Minnesota Rep. Michele Bachmann, Texas Gov. Rick Perry and, most recently, businessman Herman Cain.

Each of those anti-Romneys have proven to be something less than advertised — with the possible exception of Trump who performed roughly equivalent to the lowest possible expectations that people had for him.

Christie was touted in some circles as the true anti-Romney figure, a straight-talking anti-politician — his 2009 victory as governor was the first time Christie had run for a major elected office — who not only could win a Republican primary but would also provide a stark (and winning) contrast with President Obama.

With Christie now out of the running, conservatives as well as major donors who had stayed on the sidelines in hopes of luring the New Jersey governor into the race are faced with a decision: Do they line up behind Romney, the most electable Republican at the moment, or rally behind Perry who is likely to be the only candidate with the fundraising heft to compete with the former Massachusetts governor in the primary process?

Much of that decision could well rest on how Perry performs on two fronts over the next few weeks: fundraising and debating.

A strong third fundraising quarter from Perry — strong defined as $15 million or more — would likely allow the Texas Governor to press the “reset” button on what has been a decidedly rocky last few weeks capped off by a Post story over the weekend detailing a racial epithet visible at a hunting camp owned by his family.

Similarly, a bounce-back performance in next Tuesday’s Washington Post-Bloomberg News debate in New Hampshire could help reassure conservatives that Perry is ready for prime-time and up to the challenge of knocking off the relentlessly disciplined Romney. Perry’s struggles in three debate in the month of September helped create the “is he ready for all of this” narrative that has badly damaged him — damage evidenced by his slide in the new Washington Post-ABC News poll.

Romney, of course, won’t be a bystander in this process. Expect him to heavily court those donors who had been sitting on their wallets while Christie made up his mind with a message heavy on the idea that the party needs to unify behind him if they want to beat Obama next fall.

“There will be big financial bonus for us now that Christie is out,” said one Romney adviser. “He had frozen Jersey donors and we have a ton.”

(Romney is expected to raise between $11 and $13 million in the third quarter after collecting $18 million in the second quarter of 2011.)

Romney is also seeking to make the general election turn rhetorically as he is scheduled to deliver a major foreign policy address on Friday at the Citadel in South Carolina — a speech aimed at showing his 360-degree range as a candidate and seeking to draw a vivid comparison with President Obama.

There is, of course, the possibility that conservatives turn their noses up at the prospect of either Romney or Perry as their nominee and instead look to elevate one of the second-tier candidates.

Businessman Herman Cain is the most likely option — he is currently tied with Perry for second place in the Post-ABC poll — but his momentum may be blunted somewhat by the fact that he lacks any significant organization in any of the early states and has struggled to retain top staff.

Bachmann, who in August was widely seen as the conservative choice, has struggled mightily since Perry’s entrance into the race; news broke in recent days that two of her top campaign advisers were departing.

Some conservatives still hold out hope that former Alaska governor Sarah Palin will run but it is an increasingly small group. In the new Post-ABC poll just more than three in ten Republicans and Republican leaning independents said they wanted her to pursue the presidency.

Palin has pushed back her deadline for a decision until November.