While Jake Tapper is the obvious choice for the national media, I believe an honorable mention is due John Kass, of, of all media outlets, the Chicago Tribune.
For those unaware of Obama's origins in national politics, the Tribune took down Obama's Republican opponent with a vicious oppo-research campaign that culminated in the triumphant disclosure that the opponent, Jack Ryan, had allegedly asked his own wife to have intercourse with him in a possibly inappropriate location. The allegation was buried in a sealed divorce action, which the Trib, along with undisclosed assistance, managed to get open with some assiduous judge-shopping. The allegation was never substantiated and was denied by Ryan. However, with enough front-page screaming by the Trib, Ryan was eventually forced to resign from the race, leaving Obama to run virtually unopposed for US senator, garnering barely two-thirds of the vote.
In stark contrast, Kass, the Trib's leading columnist, has been a strong journalist keeping careful watch on the Daley Machine and its doings throughout this sad-sack state, including the crime syndicate involvement, such profiteer hangers-on like Tony Rezko, and the national spawn like Moseley-Braun, Bill Daley, and Obama.
He can tell you how Obama was brought along, and then foisted upon the national scene, and does so.
Heaven knows, he must fear for his life in Tribune Tower.