As for Texas, it is just about a one party GOP state now on the statewide level. No Democrat has won a statewide race there in ten years. The last Democratic Presidential nominee to carry the Lone Star State was Jimmy Carter, and that was almost 30 years ago.
Your argument does not stand2reason.
Some said that Specter endorsed Santorum when he was up for re-election; and, thus, Rick was obligated to do the same thing. Santorum enjoys power and has his eye on the presidency endorsing Specter to prevent another popular conservative like Patrick Toomey from saturating the market.