Just for kicks, I went and searched for the very first mention of Obama’s name on Grist. It came on 27 July 2004, the day of Obama’s fateful speech to the Democratic National Convention, in a dispatch from Mary Sullivan, a delegate. This is what she said:

Most inspiring was Barack Obama, 2004 Democratic candidate to the U.S. Senate from Illinois. While TV watchers know he made a powerful keynote address on Tuesday evening, those of us at the rally were treated to an equally powerful speech by Obama that focused solely on the environment. He spoke touchingly of his six-year-old daughter’s asthma, and about being lucky enough to be in a position to provide for her medical needs. He reminded us that environmental degradation has a disproportionately negative impact on low-income and minority people. Keep your eye on Obama. His first introduction to Democrats at the national level was greeted with enthusiasm that cannot be described. Despite having a name that doesn’t exactly trip off the tongue, he’s being talked about here as a future presidential candidate.

Then, in Amanda Griscom Little’s 04 Aug. 2004 Muckraker column: "Barack Star."