Campaign Status page, none of the prospective candidates has officially declared he is running for president--despite several having participated in a presidential debate.
Many of the candidates have formed presidential exploratory committees, and only one on the roster (Barbour) is categorized as "declined to run." This leaves some of the most well-known candidates in the nebulous "potentially running" category. One of these--Christie--has repeatedly stated he is not running. Others have not said one way or the other. How does a candidate convincingly deny that he is running for president?
The first rule is that simply declaring that one will not run for president is not enough. Today, Barack Obama is the best-known example of this principle: On October 22, 2006, Obama appeared on "Meet the Press" and said definitively that he would not run for president. Less than four months later, Obama officially announced he was running for president; he was likely preparing for the run long before that.
If a denial isn't enough, how can one can tell if a candidate is out of the race? There are a number of ways. First, a candidate who is already in the race would only withdraw if he meant it. Unless that person is Ross Perot, it simply would not make sense to get into the race and then get out if he really wanted to run. The same is true of someone who creates a presidential exploratory committee and then declines to run. Officially endorsing another candidate is one other way to make a permanent exit from the race.
A denial is also persuasive if it takes place after a candidate declares he is interested in running, or is considering it. Barbour fit into that category. For several months, Barbour attempted to create interest in his potential candidacy. When he announced he was out of the race, he knew it would put an end to that interest. Making that announcement only made sense because he had, in fact, decided not to run.
On that point, an unprompted announcement or released statement is far more trustworthy than a response to an interviewer's question (as when Obama was questioned on "Meet the Press"). Potential candidates like Huckabee and Palin will likely release statements about their intentions during the next few months. If they say they are not running, they're not running.
Ironically, the denial of an intention to run is least believable when it is consistent. During the period when Obama was denying his intention to run, he did not waffle, suggest he "might" be running, or say he would make up his mind later. He consistently denied it and moved on. The purpose was to avoid appearing presumptuous. It was simply too soon for Obama to run, because he had been elected senator so recently.
Christie faces a similar dilemma. Since he only took office in January 2010, it would appear presumptuous--neglectful of his office, even--for him to announce he is running. He can only enter the race if he is essentially drafted by the Party. The Party cannot claim to be out of options until the race is already underway. Thus, the only way for Christie to convincingly decline to run would be to either officially endorse another candidate, or remain out of the race beyond late 2011 (perhaps October or November), when it would be too late to run.