Attorney General Tom Corbett came into office four years ago with a long list of agenda items, including plans to crack down on child predators, drug dealers and abusers of the elderly.

He's done a solid job on those fronts and in pursuing illegal gun crimes in Philadelphia. But Corbett has become best known for taking on political corruption in Harrisburg.

The attorney general's wide-ranging probe, known as "Bonusgate," is focused on whether top lawmakers awarded taxpayer-funded bonuses to staffers for doing campaign-related work - which is illegal.

More broadly, the 18-month investigation has raised public awareness on the way back-room politics are conducted in Pennsylvania. Rooting out corruption and changing the entitlement culture in Harrisburg is something that has been badly needed for some time.

There's nothing like some grand jury indictments and subpoenas to change the ways in Harrisburg. Just look at how the corruption probe of City Hall changed the climate in Philadelphia.

So far, the Bonusgate probe has resulted in the indictments of a dozen state House Democrats, including former Democratic whip Mike Veon (D., Beaver) and the former chief of staff to House Majority Leader Bill DeWeese (D., Greene). Corbett says the investigation is ongoing and includes Democrats in the Senate and Republicans in the House and Senate.

TOM CORBETT

deserves a second term in office to see the probe through, and The Inquirer endorses his reelection.

Corbett, 59, is a former U.S. attorney from Pittsburgh and was an assistant district attorney in Allegheny County. He had a previous stint as attorney general from 1995 to 1997, when then-Gov. Tom Ridge appointed him to fill the unexpired term of Ernie Preate, who was convicted of mail fraud.

Between government jobs, Corbett, a graduate of St. Mary's University Law School in San Antonio, Texas, was an attorney in private practice.

No Democrat has ever won the attorney general race in Pennsylvania since it became an elected office in 1978. Democratic challenger John Morganelli, 52, of Bethlehem, has been the Northampton County district attorney for the last 16 years.

Morganelli is running on three key issues: ending predatory lending, cracking down on illegal immigrants who commit crimes, and revoking parole for violent criminals and sex offenders.

But much of Morganelli's campaign has been devoted to criticizing the way Corbett has handled the Bonusgate investigation. He says Corbett botched the probe by going after Democrats first, giving Republicans time to cover their tracks.

Morganelli says politics influenced the fact that Democrats were indicted before Election Day, but no Republicans.

Corbett says the investigation is big and complex, and that Morganelli is wrong to suggest politics dictated the timing of indictments.

The probe must be full, fair and thorough regardless of political party. If reelected, Corbett needs to follow the investigation wherever it leads. Anything less will undercut the seriousness of the charges.

The proof will be in the results.