May,22, 2008 - LOS ANGELES - The duel between Davids brought an estimated 31.7 million viewers to the Fox finale of "American Idol," a million more viewers that last year's showdown between Jordin Sparks and Blake Lewis, Nielsen Media Research reported Thursday.

That preliminary estimate beats last year's audience of 30.7 million. That would be a coup for Fox, which has seen ratings for its franchise slide during the past month. But the final competition between winner David Cook and runner-up David Archuleta proved intriguing in the final days.

Cook's transformation from soul-patched slacker to "American Idol" is complete, and his overwhelming victory probably says as much about his soulful gaze and in-season makeover as it does about his chops as a rocker.

Or maybe it says even more about who's voting these days.

Other than his hair — both on his face and atop his head — not much about the 25-year-old from Blue Springs, Mo., changed since his performance of Bryan Adams' "Everything I Do" during the Hollywood round. Back then, he was a promising "Idol" hopeful, but he didn't have the instant juggernaut feel of 17-year-old crooner David Archuleta.

And yet when Cook was crowned "Idol" on Wednesday night, it was a landslide: Host Ryan Seacrest said he'd won by a margin of 12 million votes out of the record 97.5 million cast by viewers.

"I actually walked into this with no expectations, and I'm walking out of it with no expectations," Cook told reporters backstage after his win. "This show is a springboard, but it's still a crapshoot."

From the outset, the ex-bartender provided soaring vocals and just enough outside-the-box behavior — see his rendition of Chris Cornell's version of Michael Jackson's "Billie Jean" — to keep viewers cooking up votes for Cook every week. Neither Cook nor Archuleta was ever a low vote-getter.

But it was Archuleta who always received the most praise — by both judges and loud fans — right up until Tuesday's final performance, in which judge Simon Cowell declared that Archuleta had scored a "knockout" over Cook, who sang Collective Soul's "The World I Know," U2's "I Still Haven't Found What I'm Looking For" and "Dream Big."

Or maybe being rebellious turned out to be worth the gamble for Cook; it's been suggested that a poor showing with the judges can drum up support from indignant or sympathetic voters.

Criticism may have made Cook's win sweeter for some, but don't call it an upset. Several online outfits predicted he would take home the top prize: a record contract and an SUV. DialIdol.com, which tracks busy signals on the separate phone lines dedicated to each contestant, correctly projected him the winner Wednesday morning.

So why did the older David best the younger one — the one who couldn't take a step on the "Idol" stage without a collective shriek coming up from every under-13-year-old girl in the audience?

One reason for Cook's winning appeal may be found in a rustling in the show's recent ratings: Viewership for teenagers 12-to-17 for "Idol" was down this season, and the median age of an "Idol" viewer, once in the mid-30s, is now up to 42, according to Nielsen Media Research.

Cook was, after all, the first "rocker" of many to take the crown from a steady stream of pop- and R&B-type singers. Perhaps an older contingent helped push Cook over — way over — the edge. The upper age limit was raised from 24 to 28 in season four; could another increase be on the way?

Another reason could be that Cook was so genuinely humble — and not as quiet or obsequious as Archuleta — throughout the competition, even until the very end. On Wednesday, he told reporters it was an honor to share the stage with the teenage singer from Murray, Utah. Cook said Archuleta had more talent at 17 "than I know what to do with at 25."

Cook was overcome with emotion when he won, bending down toward the stage, his eyes filled with tears when he stood back up. It was the second time in as many nights that the scruffy, grainy-voiced belter had broken down. And a few weeks earlier, when he seemed edgy and distracted, he acknowledged that he had "things going on," perhaps a vague reference to the struggles of his older brother, Adam, who is battling advanced brain cancer.

On Wednesday night, Cowell saw fit to apologize to Cook for casting him as an also-ran to Archuleta. Just before the winner was announced, Cowell uncharacteristically backtracked on his words of the night before, telling him he was one of the nicest and most genuine contestants the show has seen, and allowing that the competition "wasn't quite so clear cut as we called it."

Beyond his booming voice and continuous acclaim, Archuleta became the focus of controversy when his father, Jeff, was reportedly becoming too heavily involved in his son's rehearsals and asked by the show's producers to back off. News of such an altercation may have cost the doe-eyed crooner votes from a more knowing adult audience, who perhaps couldn't stomach the thought of rewarding a stage dad.

The only behind-the-scenes story about Cook to surface during the competition concerned his sick older brother, who made the trek to Los Angeles from Indiana to watch his brother perform as a member of the top seven finalists. Such adversity can only make someone on TV seem more human.

Whatever the reasons really were this year, in a competition that can crown a 29-year-old gray-haired Southerner one year and a cheery 17-year-old high-school student from Arizona the next, it's ultimately impossible to tell why America choose its "Idol" the way it does.