The tone of the Democratic gubernatorial campaign is changing quickly.
Candidate Rob McCord began airing the first statewide TV attack ad Wednesday. He criticizes other candidates over their stances on taxing Pennsylvania's natural gas drilling industry and singles out businessman Tom Wolf.
McCord, the state treasurer, says he's the only one who supports a 10 percent tax.
Then he says, ``Tom Wolf and the others would leave hundreds of millions of dollars in the drillers' pockets.''
Wolf's campaign is responding. It suggests McCord is playing political games and that the 5 percent tax that Wolf supports can actually win passage in a stubborn Legislature.
The other Democrats running are U.S. Rep. Allyson Schwartz and former environmental protection secretary Katie McGinty.
Republican Gov. Tom Corbett has a primary challenger from businessman Bob Guzzardi.