All over the country Republican governors are either poised for easy reelection (such as Ohio’s John Kasich and Nevada’s Brian Sandoval) or running even or better against Democrats (Wisconsin’s Scott Walker and Florida’s Rick Scott). Then there is Governor Tom Corbett in Pennsylvania. The latest independent poll has him down a shocking 49 percent to 24 percent (with a quarter of voters undecided) against Democrat Tom Wolf.

How did Corbett become such an outlier? The answers show just how much trouble Republicans get into if they allow machine politics and public-sector unions to dictate their agenda.

Corbett aides quickly attacked the messenger, sending out tweets dismissing the recent poll, from Franklin & Marshall College.

“You are unfairly influencing this election with bad polls,” claimed Corbett campaign manager Mike Barley. But no such complaints came from Team Corbett when F&M showed then–attorney general Corbett winning the governor’s race easily in 2010. In addition, other polls confirm the governor’s dire political condition: The Real Clear Politics average of all recent polls in the race show Corbett down by 17 points. That’s in a state that Mitt Romney lost by only five percentage points in 2012.

Corbett has gotten himself into this fix in two ways: First, F&M pollster G. Terry Madonna noted that four years ago Corbett ran against the political culture of Harrisburg, the state’s capital, and “its cliques, obstructionist tactics, recurring corrupt behavior, and anti-reform ethos.” But he has consistently failed to get the major parts of his agenda through a legislature controlled by his fellow Republicans. Madonna pointed out that this leads to an obvious question: “Why can’t Corbett work with his own party?”

That question leads to the second reason for Corbett’s collapse. Pennsylvania is indeed an anti-reform state. Though once dominated by a GOP machine, it gave way to a Democratic-run machine with the advent of the New Deal. Now, the Keystone State is dominated by public-sector employee unions with their hooks buried deep inside both parties.

Time and time again, Corbett’s agenda was blocked by key Republicans in the legislature. His effort to pass school vouchers was whittled down to a measly $75 million increase in tax credits for private schools. His bid to finally privatize the state’s antiquated system of state liquor stores was thwarted. Ethics reform was dead on arrival. This year, Corbett lashed himself to the mast and vowed to steer public-employee pension reform to passage. “Sixty-two cents of every new dollar in revenue, goes to the pensions,” he told groups up and down the state. His proposal to change the pension plans for all new state and public-school employees ran aground when the GOP state house blocked it.

Corbett’s conservative allies urged him to press for “paycheck protection” — blocking the state from deducting union dues from state-worker paychecks — as the key to overriding union influence in the legislature. “Wisconsin’s Scott Walker and Michigan’s Rick Snyder have both demonstrated how union power can be curbed by ending the union-only deduction-for-politics privilege,” Matt Brouillette, president of the state’s conservative Commonwealth Foundation, told me.

But at a pro-reform meeting of the Associated Builders & Contractors of Pennsylvania this spring, Corbett gave “paycheck protection” only a passing reference in his speech. When pressed by a member of the audience, he mumbled, “I’ve told everyone, if you get that bill on my desk, I’ll sign it.” But he made no special lobbying effort for the measure, just as he allowed his political team to discourage primary challenges to pro-union GOP legislators in the 2012 midterm elections. Paycheck protection died this summer. “We took an internal GOP caucus vote, and we were a few votes short in the house,” atate representative Richard Saccone told me at an Independence Hall Association event in Philadelphia this July 4th. “The unions have powerful influence on a few of our members.”

Governor Corbett’s failure to either anticipate the intransigence of some of his GOP legislators or build outside pressure on them has been compounded by his retreat on the pledge he made in 2010 not to raise taxes or fees. Earlier this year, he angered conservatives when he raised a wholesale tax on gasoline as well as a bevy of motorist fees as part of a business-as-usual transportation bill. Unsurprisingly, he has declined to repeat his pledge this year. “We can imagine what that would mean in any second term under Corbett: higher taxes,” conservative activist Bob Guzzardi tells me. Guzzardi tried to run against Corbett in this year’s GOP primary, but his petitions were challenged by four Corbett supporters and he was thrown off the ballot. Despite Guzzardi’s lack of money, Corbett clearly perceived him as a threat. A Gravis Marketing poll in January of this year found that when GOP primary voters were asked if they wanted to reelect Corbett or go for a new GOP nominee, 41 percent plumped for a new candidate and only 38 percent stuck with Corbett. In a hypothetical matchup, Guzzardi trailed Corbett, 42 percent to 23 percent, with a full 35 percent undecided.

Corbett’s problems with his base have continued. Last week’s F&M poll found that he doesn’t even command majority support among Republicans, leading Democrat Wolf by just 48 percent to 24 percent. Astonishingly, while Republicans nationwide are more motivated to vote than Democrats, in Pennsylvania it’s Democrats who are four points more likely to say they are certain to vote this fall.

Pennsylvania conservatives have often shown in the past they want more principled and effective leadership. In 2012, tea-party activist Cris Dush came within 500 votes of beating house speaker Sam Smith in a GOP primary, prompting Smith to retire this year. Dush went on to win this spring’s GOP primary to replace Smith.

The challenge Pennsylvania conservatives will face after Governor Corbett’s likely loss is how to deal with an anti-reform legislature that is apt to remain under GOP control thanks to creative gerrymandering. In the past, too many conservatives have cut them slack and allowed the party to retain quiet insider control in Harrisburg. But Corbett’s loss would be a wake-up call that the status quo is dragging Pennsylvania’s economy down and alienating the Republican party’s base.

A new approach is required. Democrat Wolf, a former finance secretary under Democratic governor Ed Rendell, has publicly said he plans to circumvent the state’s constitutional requirement that its income tax be one flat rate. Wolf won’t disclose details of his plan for a “progressive” tax regime, but its implementation could include some Obama-like dubious assertions of executive power. If Pennsylvania Republicans don’t start holding their leaders accountable by demanding pension reform and preserving the state’s flat 3.07 percent income-tax rate, they could see the state going the way of bankrupt Illinois, which has become a sordid example of just how much damage political machines in both parties can do to a once-proud state.

— John Fund is national-affairs correspondent for NRO.