On Friday, we took a look at the White House's firing of Gerald Walpin, the inspector general of the Corporation for National and Community Service, who had clashed with an Obama ally, Sacramento mayor Kevin Johnson. We concluded that, though the White House should offer a more detailed explanation for the firing, it looks like there was ample reason to get rid of Walpin.

But we're not the only ones asking for more information. ABC News reports that Sen. Charles Grassley, (R-IA) has sent a letter to the chair of CNCS asking for all relevant information and documents pertaining to the firing.

Here's the back story, in a nutshell: Walpin, a Bush appointee, had been investigating Johnson's use of federal AmeriCorps funds, dating to when Johnson ran St. HOPE Academy, a Sacramento non-profit. After concluding that Johnson had misused over $800,000, Walpin took the rare step of recommending that Johnson be barred from receiving federal funds, pending a criminal investigation. That ended up jeopardizing the city's ability to get federal stimulus dollars, after Johnson was elected mayor. But the local US attorney, also a Bush appointee, found no criminal wrongdoing in the case, and his successor formally complained to an oversight body for inspectors general about Walpin's work on the St. HOPE probe, charging that Walpin had acted "as the investigator, advocate, judge, jury and town crier."

Grassley also specifically asks for information relating to the role of the First Lady's office. That seems to come out of a story by the youth service newsletter Youth Today, which reported that, according to people in the field, "some decisions about CNCS are being made by First Lady Michelle Obama." The story also noted that last week, it was announced that Michelle Obama's chief of staff, Jackie Norris, would join CNCS as a senior adviser.

Grassley has appeared to side with Walpin for a while. In an earlier letter to Obama asking for more information on the firing, he wrote that "it appears [Walpin] has been doing a good job."

Separately, more details are emerging to suggest that Walpin was a staunch GOP partisan. In addition to being a member of the conservative Federalist Society and declaring that Massachusetts is run by the "modern-day KKK ... the Kennedy-Kerry Klan," Walpin wrote an oped for the New York Daily News in March 2008 in which he attacked Yale University for withdrawing a speaking invitation given to Bush torture architect John Yoo. And Walpin has already given an interview about his firing to the far-right website WorldNetDaily.

Given Grassley's letter, it's hard to believe we won't hear more from the White House on this. We'll keep you posted when we do.