Lehigh Valley: why not more Democratic?

[Linus Van Pelt]

The Bethlehem/Allentown area is one about which I don't know a lot, even though it's not that far from me. My mental image of it is as a sort of Scranton/Wilkes-Barre type of place, albeit historically more manufacturing-based than mining. Yet it seems more Republican than other union areas in PA - it went for Reagan both times and Bush Sr., almost went to Bush Jr. both times, and it's represented by Charlie Dent in the House. Also, it seems to be growing in population, which surprises me (Do people actually commute from here to the Philly or NYC areas?).

Any insights as to why this is?

[Linus Van Pelt]

Thanks for all the responses - I suspected that there might be some exurbia going on, but I wasn't sure.