Rasmussen has some bad numbers for Obama:

Fifty-six percent (56%) of voters nationwide disagree with Barack Obama's statement that people in small towns "cling to guns or religion or antipathy to people who aren't like them or anti-immigrant sentiment or anti-trade sentiment as a way to explain their frustrations." A Rasmussen Reports national telephone survey found that just 25% agree with the Democratic frontrunner while 19% are not sure.

Also, Rasmussen found, moderate voters disagreed with Obama 51-27. Whether Obama's comments make a difference in PA or the remainder of the primary, you can be sure the GOP will trot them out (along with some other stuff) in the general against him.