Primary Colors has done yeoman’s work tracking the representatives and their votes and graphed it all and it shows something we’ve suspected.
Republicans vote conservative even if they come from swing districts, whether it’s New Jersey or Alabama, they vote the same. Which just shows 1. that Repubs from bluer/purpler areas are awesome bullshitters come election time, 2. illustrates the failure of media to pierce the bullshit bubble, and 3. indicts voters (and especially non-voters) for rewarding such ideological rigidity that they do not agree with by either voting while ignorant or not voting at all.
You can expect nearly identical voting patterns from almost all Republicans whether you live in a swing district or an uber-conservative district.
Democrats moderate in response to district demographics; Republicans don’t. Commentators have been noting the lock-step Republican Party discipline for years, especially since the Tea Party came on the scene. The graph above is the proof.