After months of denying any possibility that he would run for president in 2012, advisers to New Jersey Gov. Chris Christie are actually considering it seriously, an anonymous aide told The New York Times.

Christie hasn't made a final decision, but his advisers have begun to strategize in earnest so that they can launch his campaign immediately if needed. One told The New York Times that a campaign could be underway within 24 hours if Christie does decide to run.

Christie's aides said he had initially been looking at a 2016 campaign, but with President Obama's approval ratings so low and voters dissatisfied with the current Republican field, he is reconsidering whether 2012 could be his moment after all.

Given the rush by many states to schedule their primaries and caucuses as early as possible, the start of the voting season could be less than 100 days away. That leaves Christie precious little time to build a campaign infrastructure that can compete seriously in crucial states like Iowa and New Hampshire.

Numerous national figures -- including News Corporation CEO Rupert Murdoch, former Secretary of State Henry Kissinger and conservative writer William Kristol -- have been urging Christie to run, and many voters have stepped forward to tell reporters that they think he is the one who can unite the Republican Party. But a successful campaign is about much more than a good reputation going in, and the bounce that comes from being the new person on the scene can't sustain a candidate for long (just ask Rick Perry).

Top-tier candidates have to raise copious amounts of money -- a challenge when entering the race so late -- and come up with a strategy for spending it. They have to recruit volunteers and staffers, work the media and set a travel schedule that takes them to both early voting states and key swing states. Meanwhile, the filing deadlines to get a candidate's name on primary ballots are fast approaching.

History is full of cautionary tales of savior candidates who never lived up to the hype. In 1992, New York Gov. Mario Cuomo considered the slew of calls for him to run for the Democratic nomination and got so far as preparing to file his papers in New Hampshire -- but he never did. More recently, in 2007, former New York City Mayor Rudolph Giuliani entered the 2008 Republican race to much fanfare and soared to the top of the polls, only to crash in the Florida primary.

Both Cuomo and Giuliani were hugely popular as New York officials, but they couldn't translate that advantage to the national stage -- not entirely, but certainly partially, due to their late entries. Giuliani also faced an additional obstacle that Christie is likely to face as well: He had bipartisan popularity in a traditionally Democratic home state, but many Republican voters at the national level didn't think he was conservative enough.

It may already be too late for Christie, hype notwithstanding. But if he is going to have any chance, he needs to throw his hat in the ring now.