CHICAGO — Illinois Gov. Rod Blagojevich dodged an army of media to report for work in his Chicago office Wednesday, amid rising cries from politicos in Illinois and Washington that he resign.

Blagojevich faces federal allegations that he tried to auction off the vacant U.S. Senate seat of President-elect Barack Obama.

Obama himself on Wednesday joined the growing chorus of officials imploring fellow Democrat Blagojevich to step down while he awaits trial on myriad federal corruption charges. "Under the current circumstances, it is difficult for the governor to effectively do his job and serve the people of Illinois," said Obama spokesman Robert Gibbs.

And U.S. Senate Majority Leader Harry Reid warned in a letter to Blagojevich that if he attempts to name someone to fill the Senate post now, the Senate will invoke a constitutional provision to refuse to seat his appointee.

"We write to insist that you step down as Governor of Illinois and under no circumstance make an appointment to fill the vacant Illinois Senate seat," Reid wrote in the letter, which is being circulated among senators. "In light of your arrest yesterday on alleged federal corruption charges related to that Senate seat, any appointment by you would raise serious questions."

Meanwhile, Illinois lawmakers prepared to return to Springfield in emergency session Monday to consider a change in state law that would fill the Senate seat with a special election, taking the decision away from Blagojevich.

That idea — which would have been viewed as radical before Blagojevich's arrest Tuesday morning — was quickly gaining overwhelming support from the state's power structure, because of widespread fears that Blagojevich might attempt to appoint someone while he awaits a trial.

"No appointment by this governor under these circumstances could produce a viable replacement" for Obama, Sen. Richard Durbin, D-Ill., said Wednesday in a televised interview in Chicago.

AT THE OFFICE

Twenty-four hours after being led from home in handcuffs by federal agents, Blagojevich, out on a recognizance bond, was greeted Wednesday morning — his 52nd birthday — by media helicopters hovering over his house, editorials in Chicago newspapers calling for his resignation and the kind of sweeping national attention he was never able to garner before he was accused of a stunning array of corruption charges.

Blagojevich stepped from his north side Chicago home into a waiting black SUV, waving briefly to reporters who had encircled the property since dawn, but making no statement.

He traveled to the James R. Thompson Center, headquarters of state government operations in Chicago, and by late morning was ensconced in his 16th-floor, glass-walled office. He spent most of the day there, as reporters gathered in lobby of the cavernous building waiting for a public comment. As of Wednesday night, he hadn't made one.

The government accuses Blagojevich of a "political corruption crime spree," in the words of U.S. Attorney Patrick Fitzgerald. Blagojevich stands accused of holding legislation hostage while pressing its proponents for campaign donations; threatening to pull promised state funds from a children's hospital unless he got a contribution; and using a state business deal with the owners of the Chicago Tribune as leverage in a failed attempt to get editorial writers there fired for criticizing him in print.

Most startling, though, is Blagojevich's alleged scheme to profit personally from his legal obligation to fill Obama's vacant Senate seat. Blagojevich is accused of plotting to negotiate an ambassadorship or other perk from Obama's White House in exchange for naming someone the president-elect would want.

'CANDIDATE 5'

He also allegedly talked of getting campaign funds from Senate candidates in exchange for the appointment. Blagojevich allegedly talked of one of them, "Candidate 5," who had offered, through an emissary, to raise $1 million in funds for the seat.

U.S. Rep. Jesse Jackson Jr. said at a news conference in Washington that he was Senate Candidate 5 in the government's criminal complaint — a man Blagojevich was secretly recorded as saying might be willing to pay money to gain appointment to Obama's vacant Senate seat.

But Jackson said: "I never sent a message or an emissary to the governor to make an offer or to propose a deal about the U.S. Senate seat."

He said he had been assured by prosecutors he was not a target of the investigation.

The case against Blagojevich, years in the making, snagged other friends and associates along the way. Most notable was Antoin "Tony" Rezko, a top fundraiser to the governor who also had raised money for Obama.

Rezko was convicted in June of fraud and bribery charges in connection with his ties to Blagojevich. He hasn't been sentenced, feeding speculation that federal prosecutors had been seeking his cooperation in going after Blagojevich.

It's uncertain they got that cooperation from Rezko, but another Blagojevich ally, John Wyma, a longtime Blagojevich friend and fundraiser, cooperated with the FBI in their probe of the governor.

Wyma has denied through his attorney that he wore a wire in conversations with Blagojevich, but he reportedly had some involvement in the federal wiretapping effort.

DEPUTY RESIGNS

In another twist to the saga rocking Illinois politics, Blagojevich's deputy governor, Bob Greenlee, resigned Wednesday.

Greenlee, 33, was promoted in June, replacing former Deputy Gov. Sheila Nix. The reason for the resignation was not immediately clear.

Fitzgerald told reporters that the government took the unusual step of physically arresting the governor while he was still in office because of concern that the alleged ongoing crimes threatened to taint the selection of the U.S. senator and cause other damage throughout state government.

Fitzgerald is the same Chicago-based prosecutor who sent Blagojevich's predecessor, Republican Gov. George Ryan, to prison on corruption charges in 2006. Media commentators and national comedians such as Jon Stewart and Stephen Colbert have marveled at the fact that Blagojevich allegedly continued engaging in illegal activity in the wake of that sobering example — and the fact that the federal investigation into his own administration has been widely known for years.

Former state Treasurer Judy Baar Topinka, a Republican who ran against Blagojevich in his successful 2006 re-election campaign, appeared on a WGN-TV news show in Chicago early Wednesday, all but gloating about his predicament. "I couldn't stop him. I couldn't handle all the money (that Blagojevich raised in that campaign)," Topinka said. "Now we know where all the money was coming from."

The Associated Press contributed to this report.