Updated

Chicago Mayor Rahm Emanuel and U.S. Rep. Jesse Jackson Jr. will be called to testify Wednesday when attorneys for Rod Blagojevich begin mounting a defense in the former governor's retrial on corruption charges, according to a source familiar with the defense plans.

Emanuel's office said Tuesday that the former White House chief of staff was notified he may be called as a witness. And he and Jackson were expected to appear in the Dirksen Federal Courthouse Wednesday, said the person familiar with the defense, speaking on condition of anonymity because the person wasn't authorized to speak publicly.

The defense attorneys have suggested they would call Emanuel and Jackson to help them argue that Blagojevich's actions and conversations were merely part of the normal give-and-take of politics and not crimes. Both men have been under subpoena in the case since before Blagojevich's first trial last year.

In deciding whether to call Emanuel or other big names to testify, Blagojevich's attorneys have treaded carefully because they know that such high-profile witnesses can backfire.

"All these witnesses can end up hurting you far more than they can help," said Phil Turner, a former federal prosecutor in Chicago. "They're land mines. You've got to be really, really careful."

Defense attorneys at Blagojevich's first trial called no witnesses, and broke a pledge that the former governor would testify. Among the calculations Blagojevich's current team has to make is whether the benefits of putting someone like Emanuel or Jackson on the stand outweigh the enormous risks.

When it comes to anyone other than Blagojevich, the defense will have little control over witnesses' answers.

"It's Defense Lawyer 101: You don't put on witnesses unless you know exactly what they're going to say beforehand," said Gal Pissetzky, a Chicago-based defense attorney who frequently argues in federal court.

Turner agreed.

"You put (Emanuel or Jackson) on and you ask a question hoping for a certain answer, and they say something completely unexpected," he said. "That's a disaster. You're standing there in front of the jury with your pants down. "

The one comparatively predictable witness would be Blagojevich. If he's been prepared well by his attorneys and can maintain his cool under cross-examination, Turner argued that the twice-elected governor could be a formidable witness.

"He has the capability, anyway, of being very persuasive and not coming across as crazy if he puts his mind to it," Turner said.

But prosecutors, all of whom have devoted years to the case, would salivate at the prospect of being able to grill Blagojevich. They would be almost certain to ask him about his profanity-laced talk on FBI wiretap recordings about desperately wanting to make money, evidence that was at the heart of prosecutors' three-week presentation to jurors.

Blagojevich, 54, faces 20 charges at his retrial, including that he sought to exchange an appointment to President Barack Obama's vacated U.S. Senate seat for a top job or campaign cash; another allegation is that he attempted to shake down Emanuel's Hollywood agent brother to raise political contributions for the governor. Blagojevich denies any wrongdoing.

His first trial ended in a hung jury, with jurors only able to agree on one charge, convicting Blagojevich of lying to the FBI.

Neither Emanuel nor Jackson has been accused of wrongdoing. But their names came up often in the first and second trials — Emanuel's name in the alleged shakedown, and both men in testimony about the Senate seat.

Blagojevich's attorneys have pointed to Emanuel before as someone they say is adept at the art of political deals, and they may hope to imply to jurors that Blagojevich, too, was merely engaging in perfectly legal deal-making.

But Turner says prosecutors could score more points with Emanuel during cross-examination.

"Prosecutors could get up there and ask Emanuel, 'Would you ever extort someone, Mr. Emanuel?' 'Absolutely, not!' he'll say. 'Because it'd be totally wrong,'" Turner said. "That would be devastating testimony to the defense. They'll want to crawl under the desk and dig a tunnel outta there."

While Blagojevich's attorneys have signaled they are considering the possibility of putting Blagojevich on the stand more seriously, there's another reason why they could have second thoughts.

In federal court, if a defendant who testifies in his own defense is convicted, that testimony could be considered perjury — a finding that could add months or years to his sentence, both Turner and Pissetzky explained.

If convicted on all counts, Blagojevich faces a maximum prison term of 350 years. Federal guidelines would dictate he'd get far less, though federal can consider multiple factors in sentencing.

Blagojevich already faces a five-year sentence for the lying conviction.