CHICAGO -- Rod Blagojevich has traveled the talk-show circuit for months, telling anyone who would listen that he's innocent of federal charges that he conspired to profit from his power as governor of Illinois to fill President Barack Obama's former Senate seat.

Now the impeached former governor and his lawyers finally are going to plead their case to a federal court jury in one of the biggest such trials in the annals of this corruption-battered state.

At the trial, which begins Thursday, Blagojevich plans to take the stand himself and tell his side again, although planting enough doubt to overcome the evidence against him could be a tough sell.

Federal prosecutors have 500 hours of secretly made FBI wiretap tapes in which they say Blagojevich, 53, is plainly heard saying that he wants something in return for the Senate seat.

"I want to make money," the bushy haired Democrat says in a telephone discussion of the seat with a lobbyist friend taped in November 2008, according to an FBI affidavit.

"I've got this thing and it's (expletive) golden, and I'm just not giving it up for (expletive) nothing," he is quoted as saying on a tape made one month before FBI agents arrived at his front door at dawn and politely notified him that he was under arrest.

Political insiders are lined up to take the stand at his trial, which could last up to four months.

They include Blagojevich's former chiefs of staff, John Harris and Alonzo Monk, who were charged in the original indictment but have pleaded guilty. Harris could back up what prosecutors say the tapes mean, while Monk most likely will be asked about how Blagojevich and his closest advisers planned to use his power in order to make money.

Convicted influence peddler Tony Rezko, a top fundraiser for Blagojevich who likely knows all the secrets of the former governor's inner circle, also could be called to testify. He is awaiting sentencing and could get a break if he helps the government.

Still, it is the tapes that are expected to be most damaging.

"You have what many consider to be the gold standard of evidence -- over 500 hours of audio tapes in the governor's own voice," said Chicago attorney and trial watcher Andrew Stoltmann.

Blagojevich and his brother, Robert, a Nashville, Tenn., businessman, have pleaded not guilty to charges that they conspired not only to sell or trade the Senate seat but also turn the governor's office into a powerful machine to pressure people for campaign money and payoffs.

They deny charges that they used the governor's power over the state pursestrings in an effort to squeeze hefty campaign donations out of a racetrack owner, a highway contractor, a children's hospital executive and even top presidential aide Rahm Emanuel, then an Illinois congressman.

"I've taken the position from the very beginning that I'm innocent of everything and anything they are falsely accusing me of," Blagojevich said in a recent television interview.

The former governor said he never schemed to sell the Senate seat but instead planned to give it to state Attorney General Lisa Madigan in a routine deal with her father, state House Speaker Michael Madigan, to push through tax cuts, a health care package and a jobs bill.

"He's going to say that he was trying to get chits in exchange for the seat, chits that he was going to cash for the good of the people," said Chicago defense attorney Ron Safer, a former federal prosecutor.

Blagojevich's lawyers said the jurors will know it's true if they hear all of the tapes and not just snippets, which they claim are all the government wants people to hear.

"It's as if someone took Abraham Lincoln's speech where he says, 'With malice toward none and charity for all,' and cut it off after the words, 'with malice,' " said defense attorney Sam Adam, a veteran of Chicago's rough-and-tumble criminal courts world.

Prosecutors are expected to say the claimed plan is largely fiction, and neither Madigan has been implicated in any wrongdoing.

Blagojevich faces a 24-count indictment charging him with racketeering, racketeering conspiracy, four counts of attempted extortion, two counts of extortion conspiracy, two counts of bribery, two counts of bribery conspiracy, one count of lying to FBI agents and 11 counts of mail fraud.

The maximum penalty is a towering 415 years in prison and fines totaling $6 million.