HARRISBURG - Pennsylvania Democrats may see an opportunity to mobilize public opinion in an move by a conservative Republican lawmaker to impeach state Attorney General Kathleen Kane.

That would be one explanation for why Ms. Kane and Senate Democratic Leader Jay Costa, D-43, Pittsburgh, chose last week to respond publicly to Rep. Daryl Metcalfe's move to seek support for an impeachment resolution.

Mr. Metcalfe, R-12, Cranberry Twp. took offense at Ms. Kane's decision not to defend the state Defense of Marriage Act against a federal lawsuit challenging its constitutionality.

Gov. Tom Corbett's general counsel is handling the case instead. The lawsuit by the American Civil Liberties Union came after the U.S. Supreme Court ruled a federal DOMA act unconstitutional.

Ms. Kane called the current state law unconstitutional and discriminatory. Mr. Metcalfe is an outspoken opponent of same-sex marriage and ran for the GOP lieutenant governor nomination in 2010.

"Impeachment is a rarely used, but extremely important, tool to address misbehavior in office," wrote Mr. Metcalfe. "Attorney General Kane's violation of her constitutional, statutory and ethical duties cannot be tolerated if our system of government is to work properly."

Ms. Kane has created a constitutional crisis by refusing to perform her assigned role and encouraging the Montgomery County register of wills to violate state law by issuing marriage licenses to same-sex couples, added Mr. Metcalfe.

Mr. Metcalfe has yet to formally introduce his resolution so it's hard to know if he's a one-man band or has support from other lawmakers.

Ms. Kane didn't wait to find out. She released a statement calling Mr. Metcalfe a "bully." She said he was playing partisan politics and had little understanding of state laws, the rules governing attorney conduct and the legal role of the attorney general's office.

"The citizens of this great Commonwealth should be revolted that a politician such as Mr. Metcalfe is attempting to thwart an independent attorney general from doing her job by using such a measure," she said. "I have never been afraid of or backed down from bullies."

Mr. Costa took to the Senate floor to urge lawmakers to repudiate Mr. Metcalfe's impeachment effort and picked up on the bully theme.

"We should not stand for or allow threats of impeachment to intimidate or bully," he said.

Impeaching Ms. Kane would have a "chilling effect" on future attorney generals trying to live under the 1980 law that defines the elective office, added Mr. Costa.

Statewide Republican officials have not issued any public statements about the impeachment resolution.

A statewide poll by Quinnipiac University last January found voters slightly in favor of same-sex marriage. Overall, 47 percent were in favor and 43 percent opposed. Support was higher among women, younger voters and Democrats and independents. Republicans opposed it 67 percent to 23 percent.

The poll surveyed 1,221 registered Pennsylvania voters with a margin of error of plus or minus 2.8 percentage points.

That poll was taken six months before the U.S. Supreme Court decision put the same-sex marriage issue on the front burner in state Capitols.

ROBERT SWIFT is Harrisburg bureau chief for Times-Shamrock Communications newspapers, of which The Daily/Sunday Review is a part. Email: rswift@timeshamrock.com.