As Allegheny County DA Stephen Zappala files charges against state Sen. Joan Orie and her sister, you can hear the licking of chops all the way from Harrisburg.

T.J. Rooney, who chairs the state's Democratic Party Committee, just sent out a press release firing a salvo at Tom Corbett, the state Attorney General and leading GOP candidate for governor. 

Corbett's failure to puruse the case -- even as the AG was looking into allegations about mostly Democratic legislators "raise[s] disturbing questions about ... whether [Corbett's] extended investigation of the legislature is swayed by political concerns," the statement alleges. The Ories, like Corbett, are Republicans.

Noting that a former intern claimed to have gone to Corbett with claims that she'd been compelled to work on political activity instead of government work, Rooney "called upon Corbett to offer a full explanation of his failure to investigate [the] allegations against Orie."

Corbett has maintained that he has investigated legislators in both parties, and indeed he is currently prosecuting Philly GOP heavyweight John Perzel. But "While the progress of Corbett's investigation against House Democrats was well-publicized at every step along the way," Rooney is quoted as saying, "very little is known about his ostensible investigation of Senate Republicans."

Corbett "either needs to do the job he was elected to do ... or step aside to puruse his higher political ambitions," the statement concludes.

Republicans, of course, will counter that the investigation of the Ories is motivated by politics; Orie herself is on record complaining that Zappala is punishing her for questioning gambling interests that have ties to his family. But this is a two-fer for Dems: It damages Corbett's political prospects, while suggesting his prosecutions are all about politics. 

Corbett's gubernatorial campaign is touting his reformist credentials heavily; obviously, the accusation that he let the Ories off the hook goes right to the heart of his candidacy. What's more, it reinforces an argument that Democrats like former Democratic whip Mike Veon have made inside the courtroom: that much of what prosecutors call "corruption" is just how business gets done in Harrisburg. 

And that, it seems, is the case that the Orie case is helping Rooney make today.