When an FBI agent called Illinois Gov. Rod Blagojevich at home to inform him of a warrant for his arrest, the sleepy governor replied, "Is this a joke?"

It wasn't. Nor is there anything funny about the corrupt way that Democrat Blagojevich ran his office. Just look at the accusations in his federal criminal indictment.

In the most appalling charge, prosecutors allege that Blagojevich and his chief of staff tried to sell the vacated U.S. Senate seat of President-elect Barack Obama to the highest bidder. The governor, who by state law has sole authority to appoint Obama's replacement, was recorded by the FBI telling an adviser that the seat "is a [expletive] valuable thing - you just don't give it away for nothing."

A three-year investigation of Blagojevich had uncovered numerous other allegations of "pay-to-play" corruption that would make practitioners of the dark art in Pennsylvania and New Jersey blush with envy. Blagojevich allegedly solicited campaign donations in return for state government contracts. He allegedly sought a six-figure job for his wife.

The governor is said to have even tried to get the owner of the Chicago Tribune to fire editorial board members who wrote editorials criticizing him. In return, Blagojevich promised the publisher tax breaks. That a governor would even consider such retribution underscores the special role that newspaper editorial pages still play in trying to hold public officials accountable. Prosecutors say Blagojevich very nearly succeeded in silencing his critics at the paper.

The governor will have his day in court, but in the meantime, he should resign. He cannot effectively govern with such serious allegations hanging over him. And Blagojevich must not be allowed to appoint the state's next U.S. senator.

Legislative leaders were attempting to pass a law calling for an immediate special election, but there were doubts that the courts would validate such a hasty move. If not, the task of appointing Obama's replacement should be given to Illinois Lt. Gov. Pat Quinn.

Who would even accept the seat from Blagojevich now, given the corrupt taint that would follow the appointee to Washington? If the governor won't quit, the state's legislature should begin impeachment proceedings.

Obama said that he was "saddened" by the charges and that he didn't have any contact with the governor about appointing his replacement.

There's nothing in the indictment to indicate Obama knew the governor was trying to auction his Senate seat. But Obama's trusted adviser, Valerie Jarrett, was once a leading candidate for the seat. Apparently Blagojevich didn't want to appoint Jarrett because no payoff was promised to him.

There are also allegations that Blagojevich was negotiating with the Service Employees International Union, which gave Obama's presidential campaign more than $13 million through its political action committee, to land a cabinet post in the Obama administration. It's unknown if anyone in Obama's transition team received the governor's indirect request. If so, what was the response?

This scandal will take months or longer to unfold, and raises the prospect of Obama or top aides giving testimony. It will be an awkward distraction around the new president, and it reestablishes the former Illinois senator's political proving ground as one of the dirtiest dens of corruption in the nation.