"I have been practicing law for 44 years. I never require a client to do what I say, but I do require them to at least listen to what I say," Genson said. "I believe in this case it would be better off, and I intend to withdraw as counsel in this case. And I wish the governor good luck and Godspeed."
To be official, his resignation as Blagojevich's attorney must take place in court. When asked when he planned to do so, Genson smiled and left.
Genson's decision Friday comes one day after Blagojevich's defense team sent mixed signals over whether the governor would file a lawsuit to block his impeachment trial in the state Senate.
Defense attorney Samuel E. Adam said Thursday that a lawsuit could be filed with the Illinois Supreme Court within days, pending a final decision.
But Genson said that he's not aware of any pending lawsuit because he and the governor's other lawyers aren't speaking to one another.
"I have no idea. They don't communicate with me," Genson said. "I have not been consulted on the impeachment decisions. I'm the only one proceeding in the Federal court." [Jan. 22: Blago's Lawyers Singing Different Tunes]
He said after Blagojevich's impeachment in the House that the Senate trial's outcome is a "foregone conclusion."
The news came as a surprise to Blagojevich, who found out of Genson's plans during an appearance on a Chicago radio show.
"That's the first I've heard of it," Blagojevich told reporters gathered at WVON-AM.
U.S. Attorney Patrick Fitzgerald said at a news conference after Blagojevich's Dec. 9 arrest that the governor and his former chief of staff, John Harris, had been on "a political corruption crime spree" and their actions would make "Lincoln roll over in his grave." [Read More on Blagojevich's Arrest]
Federal prosecutors say Blagojevich plotted to sell or trade the U.S. Senate seat vacated by Barack Obama's election. He is accused of using the financial powers of the governor's office to squeeze potential contributors for campaign money and pressuring the Chicago Tribune to fire editorial writers urging his impeachment.
He was impeached by the Illinois House and faces removal after a trial next week in the state Senate. [Read More on Blagojevich's Impeachment]
Blagojevich initially was represented by little-known Chicago attorney Sheldon Sorosky, but no one was surprised when the governor turned to Genson, a tough, aggressive courtroom warrior who hates to give up.
Genson is no stranger to political corruption cases and, like most defense attorneys, has lost his share.
He represented former Gov. George Ryan's top aide, Scott Fawell, who in 2006 was sent to prison for 6 1/2 years for racketeering. Genson also represented Ryan associate Larry Warner, also convicted.
In less recent history, U.S. Rep. Mel Reynolds, D-Chicago, for all Genson's efforts to save him, was convicted in August 1995 of having sexual relations with an underage campaign volunteer.
One of Genson's biggest wins came in the case of former state Sen. Miguel Santiago, D-Chicago. The Cook County treasurer and another official pleaded guilty to giving Santiago a no-work, no-show job on the county payroll. Santiago was acquitted in January 1999.
Genson's most spectacular victory came at the trial of R&B singer R. Kelly, who was accused of having sexual relations with an underage girl. He was acquitted of all charges.
Genson didn't fare as well at last year's Conrad Black trial. Genson and a team of other attorneys got Black off on many of the charges against him. But the one-time press baron had to go to prison for 6 1/2 years anyway for pocketing money belonging to shareholders.
Genson, who uses a wheelchair because of a neurological ailment that affects his hip, is a graduate of Northwestern University law school. But he got his first taste of criminal law as a boy, trailing his bail bondsman father through the city's tough, gritty police courts.
NBCChicago.com will offer live video of Gov. Rod Blagojevich's impeachment trial each day beginning Jan. 26.
NBC 5 Chicago will also broadcast the trial on its digital channel "NBC Plus," which can be found on Digital Channel 5.2, Comcast Cable Channel 194, RCN Cable Channel 190 and West Cable Channel 130.