Tom Corbett has launched a new ad taking his opponents to task for doubting his agenda. He plays up his pledge to oppose all new tax increases, issuing a challenge to doubters: “If any of them truly believe we can’t stop Harrisburg’s reckless spending and high taxes, just watch me.”

Corbett and his Democratic challenger from Pittsburgh’s Allegheny County, Dan Onorato, have been trading shots over the past two weeks on who is the more trustworthy candidate on taxes.