It took years to become a natural.

In 2004, Barack Obama burst through the gate when he delivered the keynote speech at the Democratic National Convention. He was anointed the Next Big Thing, but looking back, he was a personable speaker who wasn't exactly a radical reinvention of the politician.

There's a progression to be seen over the past four years of speeches, from 2004 - when he made an impact, but was in an early phase of oratorical emergence - to tonight. A snippet of a 2002 anti-war speech shows a more emotional, less controlled Obama. A speech in Selma, Ala., in 2007 showed an ability to connect with a specific audience without condescending. Last spring, he delivered a classic in his speech on race in America.

At the 2004 convention, he cut a handsome, youthful figure, but his gestures on the stump were right out of Toastmasters: folding his hands together during placid moments, gesturing with circled fingers to make a point.

The text was basically an introduction to the life story that has been his cornerstone: Kenyan father, a grandfather who was a servant to the British. His white, American maternal grandparents who served the World War II effort. It was, in style, a particularly well-done Bar Mitzvah speech.

But a closer listen to and look at the Boston speech reveals some of the elements that have made Obama not only an effective communicator, but a speaker who evokes passionate comparisons to John F. Kennedy and Bill Clinton (the latter of whom probably does not appreciate the connection).

The sound: Obama has a pleasantly deep voice, well modulated - one that finds a balance between the flatline of a John Kerry and the emotional declamations of a Jesse Jackson.

The sight: It's not just a TV age. It's about giant screens at the speeches, about close-ups, about YouTube. And at 46, Obama cuts not just an attractive figure, but a youthful one. You can say the word "change" all the time, but it helps if you look like it.

The words: Obama's lines are, contrary to popular opinion, neither particularly original nor exquisite. "A Change We Can Believe In" could be applied just as easily to a new formula of Diet Coke. (Note to Diet Coke: Please do not change your formula.)

But in those words is a constant suggestion that, appearances to the contrary, Obama is not the star, not the Messiah, not the Chosen One. Instead, he suggests in speech after speech, the American people are. His success, he implies, is the sign of a nation that has grown and is ready to change.

He also, subtly, sets himself as the alt.candidate. He'll open and close with a casual, even cool "Thanks, everyone," and, in 2006, a shockingly sincere-sounding "I'm all fired up!"

If it's a step toward the daring to elect him, anyone can feel more daring without risking all that much.

He brought all these techniques to the forefront in his speech on race - the kind of direct dealing with American reality that a man who has lived in both worlds could present. He went 16 minutes without an applause line, confident in his ability to hold attention.

In the end, the words are less important than the person presenting them. After years of American politicians debating "character," Obama tweaks the script, providing a lead actor who knows his lines and never leaves his audience looking somewhere else.