I agree that Obama has a chance to reorient American politics the way Reagan did, but I think he first needs to explain to the American public a comprehensive political philosophy...
In an age where government actions is needed, Obama needs to have a simple hook with voters to explain his philosophy, something along the lines of "Not big or small government, but effective governance." Following a period where regulators didn't regulate, because "the market" was never wrong, the public clearly believes that the markets aren't always right, but that government isn't much better.
If Obama can explain his philosophy as a shift from "markets vs. government" to "how to best utilize markets to create opportunity for the general public" has a chance to truly reorient the political landscape.
On the first point I don't think that Obama's legacy hinges on him articulating what this reader refers to as a "political philosophy" to the American public. If Obama succeeds at remaking our healthcare system, greening our economy and reorienting it for the 21st century, bringing closure to two wars, making progress on international cooperation on climate change and pulling us out of a historical economic calamity then I'd say his legacy will be secure.
It also seem to me that this writer isn't talking about an actual political philosophy in the academic sense but rather a political catch-phrase, the political equivalent of a Top 40 "hook."
Beyond that though I think that by not adopting some rhetorical short-hand Obama is making a serious statement. I believe that Obama's approach to governance and his avoidance of cheap rhetoric demonstrates that he believes our nation is at a stage where ideological shorthands won't do us any good. His approach is mature, serious and sober and altogether fitting for the challenges that we face. Now is not the time for cheap sloganeering masquerdaing as philosophy. Now is the time to roll up our sleeves and do the hard work needed to right our ship.