From Rasmussen Reports:
Election 2012: Pennsylvania Senate
All emphasis below is mine, kiddies.
The latest Rasmussen Reports telephone survey of Likely Pennsylvania Voters shows Casey leading by four, 49% to 45%. One percent (1%) plans to vote for someone else, while five percent (5%) remain undecided. (To see survey question wording, click here.)
This Pennsylvania survey of 500 Likely Voters was conducted on October 9, 2012 by Rasmussen Reports. The margin of sampling error is +/- 4.5 percentage points with a 95% level of confidence. Field work for all Rasmussen Reports surveys is conducted by Pulse Opinion Research, LLC. See methodology.