Pennsylvania's self-destructing attorney general, Kathleen Kane, should resign. This week alone, The Inquirer has reported that she disrupted a second political corruption case, while the Supreme Court upheld a probe into her dissemination of grand jury information that could yield criminal charges.

It's now clear that since her early days in office, Kane's attempts to protect legitimate law enforcement targets and smear rivals have been at odds with the public interest.

The latest revelation is that Kane undermined a 2013 investigation of a former state gambling regulator with ties to Louis DeNaples, a politically connected Scranton millionaire accused of dealings with mob figures, The Inquirer's Craig R. McCoy and Angela Couloumbis reported. Kane told aides that a prosecutor had been "overly aggressive" and unfair to DeNaples and his associate William Conaboy, another powerful political figure, both of whom were witnesses in the case.

Five months after Kane revoked subpoenas issued to the pair, a DeNaples business donated $25,000 to her campaign fund. She eventually returned the money.

The gambling regulator was being investigated for allegedly spying for DeNaples as he sought a casino license. The regulator later got a job at DeNaples' casino.

Also in 2013, her first year in office, Kane killed an investigation of six Philadelphia politicians, all fellow Democrats, saying it was tainted by targeting of African Americans. That smear was refuted when Philadelphia District Attorney Seth Williams took over the case and brought charges against all of them.

Kane is further accused of leaking grand jury information about a failed probe to the Daily News in an apparent effort to shame another prosecutor.

She feuded with fellow prosecutors after campaigning on a promise to investigate whether the Attorney General's Office under former Gov. Tom Corbett stalled the investigation into Penn State child predator Jerry Sandusky. To her obvious disappointment, she found no evidence of prosecutorial misconduct.

The Editorial Board endorsed Kane's candidacy partly because of her seeming promise as a reformer and professional prosecutor. But she has demonstrated that she is not up to the task. Given her repeated unspooling of corruption investigations and the looming possibility that she will be prosecuted herself, it is difficult to see how Kane can continue to serve as Pennsylvania's top law enforcement official.