Kathleen Kane has been state attorney general for about two months, during which she has shown no reluctance to take on Republican Gov. Tom Corbett, who also is one of her predecessors.

She has appointed a special counsel to examine Corbett's handling of the Jerry Sandusky investigation when he was attorney general. And she recently found, after a review of the governor's insufficiently transparent plan to privatize the state lottery, that it violated the state constitution and the state gambling law.

Now Kane faces a particularly vexing problem - whether to defend the voter identification law. One duty of the attorney general is to defend state laws against challenges. The voter I.D. law has been challenged on constitutional grounds in state court, and a trial is scheduled this summer.

Kane criticized the law while on the campaign trail last year, so she potentially could be in the position of defending a law that she believes should be repealed. This is not akin to a defense lawyer representing a criminal. A bulwark of American constitutional principle is that everyone deserves a defense.

Kane famously is Pennsylvania's first elected Democratic attorney general, so she inevitably would be accused of partisanship if she doesn't defend a law that was designed and supported by Republicans.

That risk also is inevitable, however. Corbett faced the same criticism when, as attorney general, he made Pennsylvania a plaintiff in the federal lawsuit against the centerpiece of President Obama's first term, the Affordable Care Act.

Kane's opposition to the voter I.D. law is admirable but also a conflict. She should leave the defense to the Corbett administration and legislative Republicans.