Sen. Barack Obama (D-Ill.) will return to Washington a changed man.

He’s now a potential 2008 presidential candidate. In the primary of pundit perception, Obama is already in the ring with Sen. Hillary Rodham Clinton (D-N.Y.).

In this new political environment, what Obama does —not just who he is — is going to get more attention.

During this last election cycle, Obama was one of the most sought-after Democrats on the fundraising and get-out-the-vote circuits. He traveled extensively, overlapping a promotional blitz for his new book, stumping for Democrats and testing the waters for a 2008 presidential run. He was so in-demand on Election Day that he holed up in a hotel in Chicago for a marathon media session — some 23 radio and television interviews.

Most of the time Obama is on the receiving end of softball interviews from the national press. But the week before last found Obama admitting he made a regrettable mistake.

The Chicago papers ran big stories about how Obama got in a land deal with a shady real estate developer, Tony Rezko. Rezko is of great local interest as a political wheeler-dealer who was indicted Oct. 5 on public corruption charges stemming from an investigation of Illinois state government.

In 2005, in simultaneous purchases coordinated from the same seller, Rezko and Obama bought adjacent parcels of land in a Southside Chicago neighborhood not far from the University of Chicago. Obama paid $1.65 million for a mansion, some $300,000 below the asking price.

After landing a big book deal after being elected in 2004, the Obamas wanted to move up from a condo. Rezko’s wife Rita bought the yard next to the Obama mansion for $625,000, the list price, planning to develop there. Obama then bought a 10-foot strip of land from Rezko to enlarge his property. Though there is a fence between the properties, Obama sends his groundskeepers over to mow the lawn.

On Monday, for the first time, Obama found himself playing defense with the press. Instead of fawning Washington journalists working up positive stories about him running for president in 2008, Obama was taking questions from Chicago’s veteran City Hall reporters about his astoundingly bad judgment. The leadoff question: “What in the world were you doing in a real estate deal with Tony Rezko?” For the next 14 minutes, Obama had what for him was a new experience: explaining himself in public for questionable personal conduct.

Obama’s inquisitors were reporters who knew him for years and were neither awed nor intimidated by him. They did not feel particularly privileged to be in his presence. For them, it was just another day at the office — another grilling of yet another Chicago pol who got caught in a sticky situation. Put another way, Obama was being treated just like everybody else.

“This is the first time this has happened and I don’t like the feeling,” Obama said. “It’s frustrating to me, and I’m kicking myself about it.”

Continued Obama, “One of the things you purchase in public life is that there are going to be a different set of standards, and I’m going to make sure from this point on I don’t even come close to the line.”

A lesson, on the road to the White House.

Sweet is the Washington bureau chief for the Chicago Sun-Times. E-mail: This email address is being protected from spam bots, you need Javascript enabled to view it