Editor's note: Ari Fleischer, a CNN contributor, was White House press secretary in the George W. Bush administration from 2001 to 2003 and is the president of Ari Fleischer Sports Communications Inc.
(CNN) -- I'm a Chris Christie fan. He's refreshing, he's raw, he takes on the big challenges, especially fiscal ones, and he's a Republican governor in a blue state, a helpful fact for a presidential candidate. But he's also late -- too late to successfully mount a winning campaign for the Republican nomination.
As the latest, and final, round of speculation about his candidacy peaks -- led by powerful contributors who see the New Jersey governor as the Republican party's best chance of winning the White House -- it's important to keep in mind how hard it is to win the presidency, or even the nomination, and why in the modern -- meaning instant everything -- Internet era of campaigning, getting in this late can doom even the best candidates.
The reason Mitt Romney is faring well so far in the campaign is that he has run for president before, making him a better candidate with a national structure in place to support him. The reason Rick Perry has hit a speed bump is that he's new to running nationally, and by getting in at the buzzer, he didn't leave himself much time or space for error. If Christie were to get in now, he would be swamped by the instant expectations of success, instant demands for access, and instant need to build a campaign apparatus that takes several months to properly create.
The fact his boosters seem to miss is that the difficulties of running nationally are exponentially greater than running in one state. And that's why it's too late for him to run -- at least to run and win.
Let's say he declares his candidacy this weekend, on October 1 -- a mere four and a half months before the New Hampshire primary, a contest where a northeastern governor like Christie has to win or come in a close second if his candidacy is to have a chance. He and his supporters will immediately be hit by the cold, harsh slap of political reality, and they will realize there aren't enough hours in the day to accomplish what they need. After the initial burst of excitement behind his announcement fades, here are the six factors which will turn acclaim into complaint:
Does he know the issues? There are back-to-back debates scheduled in Hanover, New Hampshire, on October 11 and in Las Vegas one week later. There is not enough time to get up to speed on foreign policy (What will Christie say about those Pakistani nuclear weapons, or the next tricky, obscure question?), international trade, Medicare and other non-state-specific issues, let alone opposition research so he can rebut a Romney or Perry attack. Debate preparation is time-intensive -- and that means time he's not raising money, returning calls, or hitting the campaign trail. Or will he not show up at the first debate, or two, risking the wrath of the press, which will quickly turn on him, accusing him of not being ready for prime time?
One False Step: Every candidate makes mistakes, but the earlier they're made, the easier it is for a candidate to recover and learn from them, and the more forgiving is the press, which doesn't pay as much attention to early gaffes. (Except for their treatment of Michele Bachmann, but that's another story.) There is no time left for Christie to learn. Everything he does will be magnified by the media, turning small stumbles into giant falls. Just as they're hyping his candidacy now, the press will overhype his (inevitable) mistakes the moment he declares. By waiting this late, Christie will be performing without a safety net -- and it's a long way down.
He's fresh meat: Everyone in the press corps knows Mitt Romney has changed his positions on numerous issues, and none of them cares anymore. It's old news. The political press corps will dig up all kinds of information about Christie and it will become a time-sucking distraction for him and his future staff.
He didn't return my call: In the aftermath of an announcement, he'll get flooded with calls from important people who want to talk to him and his not-yet-existent campaign staff. That's the good news -- he has supporters. But when no one returns their calls, because there is no organization and no time, it won't take long for grumbling to begin. Same thing with the press. Hundreds of reporters will expect their calls and e-mails to be returned every day. When it doesn't happen, they'll write how poorly organized he is.
He didn't respond to my invitation: Every county chairman and every political group will want him to show up at their events. It will take Christie at least two to three months to hire staff and build an organization that allows him to do the basic blocking and tackling that comes with a presidential campaign. If the infrastructure is not in place until November or December, and no one replies to these invitations, excitement turns into disappointment.
He gave his word: Christie has already said he won't run. If he changes his mind now, what does it say about his willingness to change his mind on other issues, once his word is given?
Barack Obama is vulnerable. Republican candidates have been competing for months and Christie may regret missing this chance. But unless his intention is to run, lose and learn, he likely is better off keeping his word and then working on behalf of the party's nominee to defeat Obama. The New Jersey governor is 49 years old. He's young and he has a great future in front of him.
The opinions expressed in this commentary are solely those of Ari Fleischer.