DeWeese stands accused of ordering and condoning political activity, between 2001 and 2007, by state employees who were on the taxpayer dime and time.
The onetime Democratic speaker and House leader has maintained from the start that he is not guilty.
"The allegations against Bill DeWeese are petty, and this case will go down in history as 'Pettygate,' " said his attorney, Bill Costopoulos.
Prosecutors counter that DeWeese's legislative and campaign staffs were virtually one and the same, and that DeWeese not only knew of the political activity but purposely hired people onto his legislative staff to do nothing more than election work.
"Practically every aspect of his campaign - whether fund-raising, mailers, advertising, signs or door-to-door canvassing - was performed by legislative employees," according to the 2009 grand jury presentment against DeWeese.
What's more, prosecutors allege, DeWeese threatened to fire or otherwise punish legislative employees who he felt weren't doing enough election work, particularly in 2006, when the legislature's polling numbers were at historic lows.
From the start, DeWeese's defense has been that election work did indeed take place during legislative hours - but that the legislator directed his staff to do such work on their lunch hour, or using vacation, compensatory, or personal time.
The fiery and occasionally bombastic lawmaker has said that he had fully cooperated with the Attorney General's Office, and that he had even testified before the grand jury for a full day.
He has said he believes the prosecution against him and others swept up in Bonusgate and related cases was blatantly selective and political. The Bonusgate probe began in early 2007, and was coined as such because it involved allegations (and eventually charges) that taxpayer-funded bonuses were awarded to legislative employees who did political work.
At the time, Gov. Corbett was the attorney general. Three years later, he was running for governor, campaigning heavily on his credentials as a person who has helped clean up politics in the Capitol.
Corbett has repeatedly denied any political bent to his office's investigation, pointing out that career prosecutors with no political loyalties were handling the case.
But questions have lingered, raised mostly by some of the defendants themselves. Aside from the original Bonusgate case, in which 12 House Democratic caucus members were charged, the Attorney General's Office separately charged 10 House Republicans, including former House Speaker John M. Perzel of Philadelphia, in a case that came to be known as "Computergate."
The outcomes have been mostly favorable to prosecutors: 19 people were either convicted or pleaded guilty; two were acquitted; and state prosecutors dropped the charges against one. Still, there are critics who believe Corbett went after only Democrats, or Republicans who had very little clout or power.
The Attorney General's Office has declined comment, and state prosecutors have said their political-corruption probe continues.
Corbett spokesman Kevin Harley strongly defended the investigation.
"This notion that this prosecution is political is ridiculous," said Harley, noting that the probe was conducted by career prosecutors and that the charges were recommended by a grand jury. "Those kind of accusations are just part of his delusional defense."
DeWeese was charged in late 2009 along with Democratic State Rep. Steve Stetler of York County and onetime DeWeese aide Sharon Rodavich. Stetler will be tried later this year, while Rodavich last week entered a guilty plea.
The normally loquacious DeWeese would say little last week about his trial or his strategy going forward - although he has said he is "99.9 percent" certain he will take the stand in his defense.
Does he have any nagging doubts, ones that would make him plead guilty before the case begins?
"No, never. Never in 10,000 years shall I make that plea," DeWeese said. "My presumption of innocence is more than a presumption - it is the cold, hard fact of the case."
Contact staff writer Angela Couloumbis at 717-787-5934 or firstname.lastname@example.org.