Pennsylvania Gov. Tom Corbett’s tumble in the polls has made Republicans nervous about four pivotal Philadelphia-area House districts.

Local GOP operatives fear this 2014 scenario: Corbett drags down the ticket for perennial targets Reps. Patrick Meehan, Jim Gerlach, Michael G. Fitzpatrick and Charlie Dent. Meanwhile, top potential Corbett foes count southeastern Pennsylvania as their political base, driving Democratic turnout in their suburban House districts.

“The impending blowout of Corbett could cause severe Republican losses downballot, hitting hardest in the southeast,” said a top GOP operative in Pennsylvania, who was granted anonymity to speak candidly about the governor. “The old axiom is still true that any Republican majority in Congress is built on a foundation of Philadelphia collar county Republicans. It’s an untenable situation.”

Corbett is one of the most unpopular governors in the country, and a Quinnipiac University poll released Monday showed 47 percent of survey respondents disapproved of his job performance as governor (compared with 38 percent who approved). The poll also showed 50 percent of voters surveyed say he does not deserve re-election, while 32 percent of respondents backed him for a second term.

At least one House Republican from southeastern Pennsylvania, Dent, sees his race as more dependent on national trends than local politics.

“As a member of congress, I’m generally going to be judged based on the national political environment,” Dent said in a Monday evening phone interview. “We are going to be in the midterm of a second term of an incumbent president. I’m in the party opposite to the president. I think that will likely be the trend that drives this election more than any other.”

Similarly, Gerlach noted the election is still a long time away in a statement emailed to CQ Roll Call.

“The November 2014 election is an eternity away,” Gerlach said. “If the governor can get a few good legislative victories in the next few months, he’ll be in a solid position for success next year. Otherwise, I’m focused on the work we’re doing on [the] Ways & Means [Committee] on policies that encourage hiring, investment in the United States and sustained growth.”

But also notable is how Corbett matches up against any of the top three prospects for the Democratic nomination — all of whom have a base in the Philadelphia suburbs. From the Quinnipiac survey memo:

• Former Rep. Joe Sestak led Corbett 48 percent to 34 percent. Sestak has yet to announce his plans for 2014.
• Rep. Allyson Y. Schwartz led Corbett 47 percent to 34 percent. Schwartz jumped into the gubernatorial race last month.
• State Treasurer Rob McCord led Corbett 44 percent to 35 percent. McCord has not officially announced his campaign yet, but Democrats expect him to run.

Southeastern Pennsylvania was one of the nation’s top political battlegrounds — until last cycle. Gerlach and Dent survived repeated competitive challenges since being elected in 2002 and 2004, respectively. The seats held by Fitzpatrick and Meehan have flipped back and forth between the parties over the past decade.

Republicans aimed to shore up these districts for the GOP when they controlled redistricting last cycle and were somewhat successful. President Barack Obama lost these districts by only a couple of points; meanwhile, these four members won re-election by double digits.

There are 18 months until the gubernatorial race — a lifetime in electoral politics. And Keystone State chief executives have proved invincible in their re-election bids: No governor has lost re-election in Pennsylvania in modern history.

“We’re still a long, long ways before we get to November of 2014,” said Charlie Gerow, a GOP strategist based in Pennsylvania. “The election isn’t held today. If the election were held 18 months before Ed Rendell’s re-election, Democrats would have been nervous.”

Maybe. Quinnipiac University polled the gubernatorial race extensively in 2005 — the year before Rendell’s re-election. The results showed his approval rating was never underwater like Corbett, and at his most unpopular moment that year, 39 percent of survey respondents disapproved of his job.

Rendell’s low-water mark was July 2005, when only 46 percent of respondents said he deserved re-election, while 41 percent said he shouldn’t get another term. By comparison, Corbett’s current polling is much worse.