Their pursuit of ideological purity could wind up electing a Democrat who'll smother their state's gas boom with onerous taxes and excessive environmental regulations.
The Marcellus Shale play is gigantic and just getting started. Already it's put more than $2 billion worth of royalties in the bank accounts of Pennsylvania property owners, boosted local tax revenues and created tens of thousands of new jobs.
Pennsylvania was the country's first energy state. It's where most of the coal that built America into an industrial superpower came from and where the oil and gas industries began 150 years ago.
Now the Keystone State sits in the middle of the continent's most productive natural gas field.
Pennsylvania's economy is being rejuvenated by the shale boom, but Democrats only want to fatten the state government on gas severance taxes.
Corbett knows how foolish that would be. He knows that as long as the state government doesn't kill the goose that's generating the first important economic growth spurt in a century, Pennsylvania will receive hundreds of millions of dollars from its reasonable gas drilling impact fees.
Corbett may not be as ideologically pure as some conservatives wish, but they should remember a few things.
They should remember my father's 80-20 rule for Republicans - that if you're with me 80 percent of the time, I'm with you.
And they should remember the Bill Buckley Jr. rule - that Republicans should nominate the best conservative who can win in the general election.
So my Pennsylvania friends, you may not love Gov. Corbett. But on Election Day you better like him enough - and appreciate him enough - to vote for him.