It was the big story on Philly.com yesterday morning, and for understandable reasons. In a world where our necks were already sore from the 24/7 never-ending tennis match between MSNBC and Fox, between the Obama-hating right and the Tea Party-loathing left, this one was a head exploder. How could such a prominent Pennsylvania Democrat -- a man who not only sat at the right hand of Ed Rendell in Philadelphia City Hall for a half-dozen years but hosted President Obama in his own home -- turn around and endorse Gov.