Congress is expected to hear testimony Wednesday from Monica Goodling, who served as a key link between the White House and the Justice Department as decisions were made to dismiss eight U.S. attorneys.
She may give congressional Democrats some of the answers they've sought regarding the motive for the firings.
Most of what Congress knows about the White House's involvement in the firings has come from indirect clues dropped in testimony by other officials. The White House will only let Congress interview the president's advisers in private without an oath or transcript.
That's why Congress was eager enough to hear from Monica Goodling that they granted her immunity to testify. As the Justice Department's White House liaison, she may be able to give the first clear view into the White House's role.
Harvard Law Professor David Barron says the arrows pointing to the White House may also give a clue about why Gonzales remains in his job despite bipartisan calls for him to resign.
"The more that these investigations begin to touch on the conduct of the president himself, the more need there may be for the president to keep the attorney general in office, for fear that if he goes, then the president stands exposed directly to the investigations," Barron said.
Before the scandal exploded, a top aide to the deputy attorney general testified that the White House played a minor role in the dismissal of the prosecutors.
E-mail has since revealed that the idea to fire the U.S. attorneys originated at the White House.
And when Attorney General Alberto Gonzales' former chief of staff, Kyle Sampson, testified before Congress about who made the final firing decisions, he said this:
"The decision makers in this case were the attorney general and the counsel to the president."
That places the White House at the beginning and the end of the firing process. But the big question that no one has answered is who handled the middle? How did the names on the list get there in the first place?
Attorney General Alberto Gonzales has told Congress that he doesn't know.
"What I understood was that the recommendation that would come to me would be a consensus recommendation of people that I trusted," he said.
White House involvement in U.S. attorney hirings and firings is perfectly acceptable unless partisan politics played a role where it shouldn't have. And in this case, there are allegations that politics influenced the firings.
For example, the Senate ethics committee is investigating whether Sen. Pete Domenici, a New Mexico Republican, improperly pushed U.S. Attorney David Iglesias to indict Democrats before the 2007 election.
Iglesias was later fired. Gonzales has testified that he doesn't know who first suggested Iglesias be dismisssed, but people at the White House expressed concern.
"I'd heard concerns raised by [presidential adviser Karl] Rove," Gonzales told Congress. "And what I know today ... is that there was a meeting in October with the president in which the president, as I understand it, relayed to me similar concerns about pursuing election fraud."
Rove also played a role in the dismissal of Arkansas' U.S. attorney. The new prosecutor there, Tim Griffin, worked for Rove. In fact, the Justice Department had to backpedal from a letter to Congress that said Rove played no role in the replacements after internal e-mail showed that Rove was very involved.
And last week, the White House unexpectedly popped up in another Justice Department controversy.
Back when Gonzales was White House counsel, someone sent him to Attorney General John Ashcroft's hospital room.
Even though Ashcroft had signed his authority over to Deputy Attorney General James Comey, Gonzales urged Ashcroft to override Comey and authorize the president's secret domestic spying program.
Comey also said he had "some recollection" that President Bush was involved enough to make a call to Ashcroft's wife, telling her that Gonzales and White House Chief of Staff Andrew Card were on their way to the hospital to see her ailing husband.
"I don't know that for sure," Comey said, but added that the call to Mrs. Ashcroft "came from the White House."
The day after Comey's testimony, a reporter asked President Bush whether he placed the call.
"There's a lot of speculation about what happened and what didn't happen," the president said, adding that he wouldn't talk about it.
Earlier this week the president said Gonzales has done nothing wrong, and Mr. Bush continues to stand by him.