CHICAGO -- On just his 10th day in office, Chicago's new mayor found himself on the witness stand in the federal corruption trial of a former governor, testifying just after a congressman who talked about money and political deals.

Rahm Emanuel's appearance, the most anticipated by a Chicago mayor in a federal courtroom in decades, was over in just five minutes.

Even in a city renowned for its unholy mix of politics and graft, Emanuel's courthouse cameo on Wednesday brought the limelight back to former Gov. Rod Blagojevich's retrial on charges that he tried to leverage his office for personal gain.

Blagojevich plans to take the stand himself, his spokesman said. Glenn Selig told The Associated Press it wasn't immediately clear just when that might happen, but court discussions Wednesday evening about FBI wiretap evidence indicated it could be Thursday when the defense resumes its case.

Emanuel testified that, in his former job as chief of staff to President Barack Obama, he knew of no deal in which Blagojevich had asked for a top job in exchange for appointing Obama's preferred candidate to the president-elect's vacant Senate seat in 2008. Among the 20 charges that Blagojevich faces are several involving allegations that he tried to sell or trade the seat.

While it's unclear whether the mayor helped Blagojevich's case, the testimony by U.S. Rep. Jesse Jackson may have backfired on the defense.

Jackson testified that he never told anyone that his supporters would raise millions of dollars for the former governor if Blagojevich named Jackson to the senate post. Jurors in the case heard earlier testimony that a Jackson supporter had made that vow.

In their cross-examination, prosecutors took advantage of Jackson's appearance to ask about an unrelated incident, previously reported by the AP, which could prove damaging to Blagojevich in the jury's eyes.

Under questioning, Jackson confirmed that Blagojevich had once considered Jackson's wife for a position as head of the Illinois lottery. But Jackson said his wife didn't get the promised appointment after Jackson refused to give Blagojevich a $25,000 campaign donation.

Jackson said when he met with Blagojevich in 2003 after someone else got the job, Blagojevich apologized that the appointment didn't pan out but made it clear the donation was at least part of the reason why.

"He snapped both fingers and said, `You should have given me that $25,000,"' Jackson said, pantomiming a pose from the governor's idol, Elvis Presley.

"It became increasingly clear to me that the governor of Illinois was trading..." Jackson began before being cut off by an objection from Blagojevich's attorneys.

In a trial that had been a drab echo of Blagojevich's circus-like trial last year, the Emanuel and Jackson appearances marked the first time jurors have heard from any of the high-profile political figures whose names have been thrown around in the case since Blagojevich was led away from his house in handcuffs more than two years ago.

For the first time in this trial, dozens of people lined up outside the courthouse to attend, filling not only the main courtroom but another room down the hall, where they listened to the proceedings piped in on speakers. Another crowd is expected to line up if Blagojevich himself testifies.

Blagojevich did not testify in his own defense at the first trial, after repeatedly vowing to do so. The jury deadlocked on 23 of 24 charges against him in that case, convicting him only of lying to the FBI.

The former governor, who denies any wrongdoing, faces 20 charges at the retrial. Among the other allegations is that he attempted to shake down Emanuel's Hollywood agent brother, Ari, to raise political contributions for him. On Wednesday, the mayor said he was never asked by Blagojevich to have his brother raise money.

Wednesday's most anticipated moment was something local political scientists and historians say they can't remember happening in decades: a sitting Chicago mayor taking the witness stand in a federal courtroom.

Officials don't recall that the just-retired mayor, Richard M. Daley, ever did so in his 22 years in office, despite a number of federal corruption trials involving some of his top aides. It may have been back in 1970, when Daley's father, Mayor Richard J. Daley, was called to testify at the famed Chicago Seven trial. In that case, anti-war protesters were tried on charges stemming from violence during the 1968 Democratic National Convention.

"Many spectators had waited in line all night, camping out in sleeping bags for a chance to see the defense attorneys try to tear the mayor apart," wrote Adam Cohen and Elizabeth Taylor in their biography of Daley, "American Pharaoh," noting that he kept his famous temper in check.

On Wednesday, Emanuel seemed bored at times, and then was gone as briskly as he arrived. It was a sharp contrast with the 12 grueling hours he spent testifying in December during a hearing over his residency -- a battle he ultimately won, preserving his eligibility to run for mayor.

Blagojevich's attorneys had suggested they wanted Emanuel and Jackson's testimony to help them argue that the former governor's actions and conversations were merely part of the normal give-and-take of politics, not crimes. While still unclear whether it helped Blagojevich, few think Emanuel stood to lose from being associated with Blagojevich again.

"How could it hurt him?" said Paul Green, a political scientist at Roosevelt University who attended court. "If he had a wound he wasn't on (the witness stand) long enough to bleed."