KEY POINTS:
Nobel prize-winners from the University of Chicago are so thick on the ground on the street where Barack Obama and his family now live that even the real estate agents have advanced degrees.
One of them, Stephen Parker (PhD, Egyptology) was passing the pile that is the Obama home on Saturday morning, when he saw his boss, Donna Schwan, now a thorn in the side of the Obama campaign.
With snow piled up on the footpaths, they chatted in the middle of the road, watched by a team of anxious secret service agents providing round-the-clock protection to the man who could soon become President.
As many voters go into a collective swoon over the charismatic Barack Obama, the candidate who promises to help Americans feel good about themselves and their country once again, Schwan is urging a little caution.
"I've been there," she says. "It's like going on a hot date with a cool guy, you just don't want to ask too many questions and ruin the dream."
What she was referring to is a simmering controversy about the nature of Obama's relationship with Antoin "Tony" Rezko, a developer who was thrown in jail last week ahead of a major corruption trial.
Chicago, the most political of American towns, is where Obama and Clinton's destinies were shaped.
Clinton moved away a long time ago, but she has lots of friends and supporters here. Even at the nearby Valois restaurant, Obama's favourite breakfast spot, I bumped into a woman who went to high school with Clinton.
"I think he was more than a little naive to get hooked up with Rezko," remarked Karen Dennis, "but he is essentially a decent guy."
Whoever comes out on top in the Super Tuesday vote, a bitter struggle to become the Democratic nominee is expected to drag on for months. There is still plenty of time for mud to fly and the back-story of the political fixer, "slum landlord" and alleged criminal Rezko to become more familiar to American voters.
It's a story that can easily be manipulated, and in the hands of Obama's enemies could soon eclipse the uplifting story his work as a community organiser and his efforts to rebuild the lives of black and Hispanic workers shattered by unemployment.
The story of his efforts to get asbestos removed from tracts of public housing built in the midst of at least 50 toxic dumps may be overshadowed by his links to the moneyman behind so many Illinois political leaders. Like them, Obama accepted contributions from Rezko, first when he began his political career to the Illinois Senate in 1995, and while he was going on to achieve national prominence.
Obama began his life as an organiser in Chicago, walking the streets of Altgeld Gardens, a blighted neighbourhood where black soldiers returning from World War II were housed in virtual isolation from the city.
Linda Randle, 53, worked with him on the asbestos issue and now helps at campaign headquarters.
"He was a good listener, he walked the neighbourhoods and talked to people about their problems," she said.
In almost every speech he makes, Obama harks back to his days as a community organiser. In a recent debate he contrasted his time spent working with the poor on the South Side with the six years Clinton spent on the board of Wal-Mart, something Democratic voters are deeply uneasy about.
Clinton snapped back at him with her first public mention of the Rezko affair, calling him a "slum landlord". Since then there has been a truce between the two campaigns. But as soon as Rezko's corruption trial starts in two weeks' time, the questions about Obama will resume again.
Obama successfully pushed back at Clinton's allegation that he represented Rezko as a lawyer.
Should Obama win the Democratic nomination, the attack dogs of the Republican Party will be all over the "Rezko scandal".
Obama will be attacked for actions which though perfectly legal have left him vulnerable on one of his key selling points: his good judgment.
He now describes as "boneheaded" a financial deal he made with Rezko to buy a strip of land, just 3 metres wide.
His difficulty is that he made the property deal at a time when his political sponsor and former close friend Rezko had been indicted on federal corruption charges, an affair that was blasted all over the Chicago media.
- INDEPENDENT
