It's a shock but hardly a surprise that criminal charges of perjury, obstruction and abuse of office were filed Thursday against Pennsylvania Attorney General Kathleen Kane.

The allegations have been pending for eight months, recommended in January by a statewide grand jury. The judge overseeing the case referred it to Montgomery County District Attorney Risa Vetri Ferman, who filed the charges Thursday.

Add to that the fact there is a growing succession of state-level political figures in Pennsylvania who have been accused and convicted of criminal abuses of office.

- Treasurer R. Budd Dwyer, a Meadville native, was found guilty of bribery in 1987; he fatally shot himself during a news conference before he could be sentenced.

- Auditor General Al Benedict pleaded guilty to federal racketeering and tax fraud in 1988. He served two years in prison.

- Supreme Court Justice Rolf Larsen was convicted in 1994 of illegally obtaining prescription drugs. He was impeached by General Assembly.

- Attorney General Ernie Preate pleaded guilty to mail fraud in a 1995 plea deal. He served 11 months in prison.

— Supreme Court Justice Joan Orie Melvin was convicted in 2013 of theft of services and conspiracy. She was sentenced to three years of house arrest.

Kane is the second row officer this year to face criminal charges. Treasurer Rob McCord resigned in January after admitting he tried to extort campaign contributions from contractors doing business with his office. In February, he pleaded guilty to attempted extortion.

It was Preate, himself a former Pennsylvania attorney general, who offered advice to McCord. In a Jan. 31 report in the Harrisburg Patriot News, Preate praised McCord for the way he admitted to his crime and pleaded guilty.

McCord “has the same problem I had. A campaign violation,” Preate said. “It has nothing to do with the office. It has to do with the campaign. That's enough to trip you up.”

A guilty plea “will give him an opportunity to start his life all over again just as I did,” Preate added. “I'm a pretty successful attorney. You just got to get it behind you.”

Preate's words are telling for several reasons:

• Harrisburg row office jobs have two distinct elements: the job itself, and the job of raising campaign money to get the job. The fundraising part is time-consuming, difficult and laden with regulations, making it difficult for many to perform the functions of the office.

• Violations happen with enough frequency that it's prudent for some, like McCord, to learn from the prior experience of people like Preate. Recovery from a criminal conviction has become just another part of the career.

• Politicians should learn from the mistakes of others and refrain from repeating them, but that doesn't appear to be happening.

• When they do get caught, politicians like Preate and McCord promptly admit guilt without much remorse, as if they'd known the odds of getting caught.

Kane, at least, has steadfastly denied any wrongdoing. She has vowed to fight and to seek re-election in 2016.

Gov. Tom Wolf, a fellow Democrat, has urged Kane to step aside until her criminal case is settled. For the good of all Pennsylvanians, and for her own good as well, Kane should heed the governor's advice.