Chris Christie's speech at the Ronald Reagan Presidential Library on Tuesday did not include a declaration of his presidential candidacy -- but it didn't rule one out, either.

Christie, the first-term governor of New Jersey, has said numerous times that he will not run for the Republican presidential nomination -- but that hasn't stopped his supporters from urging him to fill what they see as a void in the current Republican field. And when he announced that he would be giving a big speech at the presidential library of perhaps the most-loved Republican of modern times, speculation ran rampant that he would finally announce his bid.

Alas, he announced no such thing.

Instead, he delivered what The Wall Street Journal described as a muscular plea for national unity. He didn't even mention the presidential rumors until an audience member brought them up in the second question of a Q-and-A session after the speech.

Even then, he did not give a straight answer. He pointed to an online video montage of his previous denials and said, Those are the answers, but he didn't outright repeat his denial. It comes to the same thing, really, but for the people who see him as the savior of the Republican Party, it was just enough to keep hoping.

When another audience member begged him to run, he answered, once again, with a careful non-denial: That heartfelt message you gave me is also not a reason for me to do it. That reason has to reside inside me. That's what I've said all along. I know without ever having met President Reagan that he must've felt deeply in his heart that he was called to that moment to lead our country. And so my answer to you is just this: I thank you for what you're saying.

These non-denials are not accidents, but they are also not indications that Christie will run. He almost certainly will not.

It might already be too late for him, anyway, despite his popularity and the heavy media attention and the pleas from voters like that audience member in California. Given the increasing number of primaries and caucuses being crammed into January and February, it is clear that September 2011 is very different from September 2007 in terms of how far along the race is. Even popular candidates have to raise money and build campaign infrastructure, and Christie would have a very tough time doing that.

Also, despite his image as someone who could unite the Republican Party, in reality, Christie would be hard-pressed to win the support of the conservative voters who make up the most powerful force in the Republican electorate right now. Time magazine's Michael Crowley compared him to Rudy Giuliani, who entered the 2008 race riding high on his reputation for pushing through Republican policies in a Democratic state but ended up performing abysmally in the primaries.

That is probably an apt comparison, and Christie is not likely to stake his reputation and his successful New Jersey career on a long-shot candidacy.