The term "Blue Firewall" really isn't justified. Just because certain states haven't voted Republican since Reagan and HW Bush doesn't mean that the GOP is unable to win their electoral votes. The reason Republicans have sucked so recently in Presidential politics is because they put up a decrepit Senator in 96, a Neo-Con in 00 and 04 who had no cross-party appeal, and another decrepit Senator in 08 only with a loon as his running mate to top it off. Perhaps for 2012 they should be thinking of getting Gregg, Daniels, Ryan, Portman, or perhaps someone else currently out of there that is out of the spotlight besides the unappealing field of Pawlenty, Huckabee, Romney, Palin, Pataki, Barbour, etc.
It's justified.
George W. Bush was a war time president. There is no excusing his inability to get the nation behind him let alone his inability to break through that "blue firewall." Especially given he's the first Republican president who has never once won the likes of California, Connecticut, Illinois, Maine, Michigan, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, and Wisconsin.
None of the others you've mentioned as potential Republican nominees for 2012 has … "potential."