What if Blagojevich had not been arrested? Whom, then, would he have chosen to replace Barack Obama in the U.S. Senate? To find out, we talked to a former top Blagojevich aide who was present for some of the governor’s discussions about the seat. According to the source, who spoke only if his name was withheld, the governor hadn’t made up his mind by the time of his arrest, but he had a short list of leading candidates—or, at least, a list of “ones he talked about the most.”

Here are the main contenders and Blagojevich’s reasons for liking or not liking them, as described by the aide.

LISA MADIGAN
“Lisa was probably the frontrunner. [She] was brought up weeks before the election. It was partially to make a deal with her old man on health care and on the capital bill—and also to get a rival out of the way.”

JESSE JACKSON, JR.
“Just because he was the black candidate. But Rod didn’t like Jesse . . . and he didn’t like how much Jesse was campaigning for the seat.”

JAN SCHAKOWSKY
“Just because she bothered him a lot about it.”

VALERIE JARRETT
“Elitist. Rod didn’t think the black community would’ve gotten their value with her . . . didn’t think [they] would think she was one of them.”

TAMMY DUCKWORTH
“The sentimental favorite, but for some reason he kind of dismissed her. He didn’t think she would be a good Senate campaigner.”

DANNY DAVIS
“Was really making a push. Rod liked him. He thought he was honest.”

AND WHAT ABOUT OPRAH?  During his late-January media blitz weeks after his arrest, Blagojevich told ABC’s Good Morning America that he had even considered OPRAH WINFREY as a potential Obama successor. Most dismissed the claim as a publicity stunt.

“She was legit!” the source insists. “Oprah was someone Rod really thought a lot about. I think it had something to do with Schwarzenegger—we were trying to find celebrities who take on causes, who, maybe, would be a good senator. So, we thought of Oprah.”

Oh, what could have been . . .

Photography: (Madigan and Jarrett) Chicago Tribune photos by Zbigniew Bzdak, (Duckworth) John Gress/Reuters, (Winfrey) Anthony G. Moore/Photorazzi