By Jon Frandsen, Senior Editor August 27, 2008 First Hillary Clinton and then John McCain battered Obama for being the rhetorical equivalent of a pretty boy -- all sparkle, no substance. And Obama appears to be taking the criticism seriously -- to the point of promising that his speech Thursday night will be far different from the one he gave four years ago that transformed him from an obscure state senator to a national figure overnight. We don't know what Obama means when he promises to deliver a speech that is "much more workmanlike" by spelling out specific policies, but it would be a huge blunder to depart too much from the tone and focus of his 2004 convention address.If anything, Obama needs to remind people just what it was that caused such an incredible stir back then -- and it sure wasn't a detailed health care plan or a promise of tax cuts.Nearly two years of intense campaigning is pretty much like being tossed into a Cuisinart -- a candidate's image becomes a whirl of charges, countercharges, cliches, gaffes, mini-dramas and soundbites. Obama will never have a better opportunity to try to piece those shards of impressions back into an entire candidate with a vision of what America is and what it can be like than he will Thursday night.What made Obama's speech so compelling four years ago was that it wasn't a wonky litany of policy fixes or political cures for whatever ailed the listener. To Americans bone weary of the fractiousness and hostility of the past decade in Washington, Obama decried the politics of division and the Balkanization of America into little more than self-interested, self-contained demographic groups. "The pundits like to slice and dice our country into Red States and Blue States...but I've got news for them, too. We worship an 'awesome God' in the Blue States, and we don't like federal agents poking around in our libraries in the Red States. We coach Little League in the Blue States and yes, we've got some gay friends in the Red States." Sponsored Content Such sentiments didn't resonate with many Americans simply because it was a nice speech. Obama put his finger on the sources of tremendous dissatisfaction and cynicism that have turned so many Americans off of their government -- but that was four years and a kajillion trips in the Cuisinart ago.Of course Obama has to go beyond those sentiments and explain to the country what he wants to accomplish and how he would go about getting there. He will be the party's nominee Thursday night, not the keynote speaker he was in 2004, and he has to demonstrate the kind of solidity and wisdom expected of a global leader. But what ails America is not a dearth of policy ideas. Plans for overhauling the tax system, expanding health care, creating jobs, controlling nuclear materials are available by the hundreds and are just a few mouse clicks away.Four years ago, Obama surprised convention watchers by explaining so eloquently what he thought did ail the country and made a convincing argument that things not only should be but could be different. If Obama can't do that again, he's probably already lost.