Capitolwire Bureau Chief Pete DeCoursey has an interesting peek behind the scenes of the Legislative Reapportionment Commission, and how the five-member body is likely to shuffle the state’s Senate districts.

LRC members are the four caucus leaders (PA Sen. Dominic Pileggi and Rep. Mike Turzai, Republicans, and PA Sen. Jay Costa and Rep. Frank Dermody, Democrats), plus former state Superior Court President Judge Stephen McEwen (a Republican, but sworn to impartiality).

At issue: the LRC’s longstanding tradition of handling the shift of PA Senate districts. Typically, the Commission allows whichever party agrees to relocate a seat to draw the new district wherever it is moved. This year, however, the areas of population decline are mostly in western PA districts represented by Democrats. Most of the state’s growth occurred in Republican areas like south central PA, the Philly exurbs, and the Poconos.

And scene:

HARRISBURG (Oct. 10) –Senate Majority Leader Dominic Pileggi, R-Delaware, is declining to comment on his plans and those of his caucus as he attempts to get the best possible map for new districts for Senate Republicans.

But Senate Minority Leader Jay Costa, D-Allegheny, says he expects the judge in charge of breaking any ties in Senate redistricting will stick to a simple, historical precedent: the party that lets a seat disappear in one region gets to draw it in another region.

….

Costa is pushing to save all the current western seats by moving them, and the seats next to them and the seats next to them, eastward. That’s the only way to avoid moving a western seat. It also likely changes the districts of too many senators too much to happen.

The Senate Republican plan would move two Senate Democratic western seats, but that probably is just a tactic so McEwen will move one Democrat as a compromise.

….

So is Costa right about that precedent, and that McEwen will enforce it?

Hard to say. First, on the merits, Republicans will argue that the west has lost two Senate district’s worth of population, and those seats should move to where the people moved to: central and southeastern Pennsylvania, and the Poconos.

And they can certainly point to the numbers: Democratic senate districts have led the western exodus, compared to GOP districts out there.

…

Which opens up another can of worms: Strategically, if McEwen – since he is the only person who can determine how many seats are moved and where they will go – decides on an “if you move it, draw it” policy, things get interesting.

Does Pileggi then agree to move a western seat, perhaps if one of Sens. Jane Orie or Mary Jo White retire from the northwest, or Sen. Jane Orie’s legal problems get worse?

In a demography class, anyone who didn’t move a seat to south-central Pennsylvania isn’t getting an A.

But neither party wants the new seat created there. Pileggi doesn’t want to add a new Tea Party senator, and Costa, even if a new GOP seat is created, wants it someplace where it gives him new opportunities.

Subscribe to Capitolwire here.