The latest numbers from Harper Polling show Gov. Tom Corbett in command of a hypothetical Republican primary, although he falls just shy of the 50% mark.

He leads Montgomery County Commissioner Bruce Castor 49% to 21% among likely Republican voters with 30% not sure.

For an incumbent governor facing the guarantee of a tough general election fight, it’s unwelcome news. The findings of this poll match those of a January Quinnipiac survey that found only 49% of Republicans thought Corbett deserves re-election. His approval rating was 41% among Republicans according to a February Franklin and Marshall poll.

It’s the second poll of the GOP primary. Public Policy Polling found in early January that Corbett lead Castor 51% to 11%.

The gender gap that has hurt Corbett’s approval ratings for months stung him in this poll, too. While the Governor lead by 41% among men (61% to 20%), he wins women 36% to 22%, a margin a third the size.

Harper polled 274 Republicans and 292 Democrats via interactive voice response dials from Feb. 27 to 28. The margin of error is plus or minus nearly 6% for Republicans and Democrats.

It’s important to note that in a poll with a relatively small sample size of decided Republicans, the margin of error is much higher in the cross tabulations like the ones that follow (breakdowns along age, geographic regions, etc). Nonetheless, it’s interesting to read the tea leaves.

The numbers seem to offer no special meaning for Castor beyond his role as an alternative to Corbett.

Indeed, geographically speaking, Castor’s home base in southeast Pa. does not offer him a boost. He takes 21% there just as he does statewide. Corbett’s base in southwest Pa. is more favorable to the incumbent. He leads there by 39 points, 52% to 13%. Castor is strongest in the State College/north central region (Penn State country, interestingly). There he has 30% to Corbett’s 45%.

Castor is most competitive among voters ages 18 to 35, where the two men are tied at 34%. Corbett’s strongest age range is the 46 to 55 bracket (56% to 18%).

Corbett leads among self-identified ‘very conservative’ voters 59% to 19% and ‘somewhat conservative’ voters 53% to 19%, while Castor leads among moderates (41% to 26%) and liberals (50% to 0%)* That result also echoes the PPP poll, which showed Castor similarly strong among moderate and liberal Republicans. It contradicts the actual contours of the campaign thus far, in which Castor has endeavored to run to Corbett’s right on numerous issues.

*That 0% is a good example of how the small sample size means that cross tabs are less meaningful.

Democratic primary

Former Congressman and 2010 Senate candidate Joe Sestak leads with 20% statewide, followed by Congresswoman Allyson Schwartz at 19%. Sestak has made only vague statements about the possibility he might run. Schwartz appears by all intents and purposes to be moving toward a bid.

Pa. Treasurer Rob McCord came in third with 7%, followed by Philadelphia businessman Tom Knox at 3%. Two cabinet secretaries from the Rendell administration took 1% each: DEP Sec. John Hanger and Revenue Sec. Tom Wolf. Hanger has declared his candidacy; each of the others has indicated strong interest.

It’s the first head to head poll of the Democratic gubernatorial primary, and with May 2014 a full 14 months away, it’s little surprise that 50% of voters are undecided. As with the Republicans, a sample size of 146 decided voters means that the margin of error will be much higher in the cross tabs – a towering 8%. Thus the margins aren’t extraordinarily significant (except perhaps SEPA, where there were fewer undecideds).

4 of the 6 share a geographic base: southeast Pa. In that region, Schwartz has a strong lead. She takes 44% compared to just 17% for Sestak, 4% for McCord and 1% for Knox.

Sestak took at least 21% in each other region of the state except northwest Pa.; his strongest region was the Lehigh Valley at 33%.

McCord pulled 13% in northwest Pa., Knox took 11% in northeast Pa., Hanger won 5% in northeast Pa., and Wolf got 3% in south central.

The poll shows a big opening for a western Pa. Democrat to jump into the race. The highest numbers of undecideds by region were west of the Susquehanna River: northwest (80% undecided), southwest (59%), south central (58%) and north central (56%).

Women went for Schwartz over Sestak 20% to 17%; men went for Sestak 23% to 16%. Sestak lead among seniors 66 and older with 23% to Schwartz’s 12%. He also won self-identified liberals, 25% to Schwartz’s 23%.