Since it seems like people here don't want Sestak to run, tell me: would you honestly support Casey over Sestak in a Democratic primary?
I, for probably the only one, completely support Casey. He is my favorite Senator, and I wish more Democrats were like him ideologically. If I lived in Pennsylvania, I would actively volunteer for his campaign in a heartbeat. I definitely don't speak for most liberals though.
That said, if Sestak runs, it is hard for me to see Casey losing anything whatsoever outside of Philadelphia, Montgomery, and maybe a few other collar counties.