As it turned out Bush won the 2004 election carrying along a plus 4 in new Senate seats resulting in a 55 to 45 Senate. It did not matter if Specter lost in the primary to Toomey or if he lost in the general election. Trying to make the case of holding the Senate for the Republicans over a single state election is silly unless you have a crystal ball that can tell the outcomes of future events. I have little doubt that the new Republican head of the Senate Judiciary Committee would have supported the President’s SCOTUS nominees.
The only thing that makes sense of the Santorum’s endorsement of Specter was he supported the GOP party favorite incumbent over the primary challenger. As in being a GOP-e team player.
Santorum was a GOP-e player re Specter in 1996...
(excerpt): “And as for the pro-abortion-rights presidential candidate Santorum endorsed, when Specter launched a long-shot bid for president in 1995, Santorum — his fellow Pennsylvanian — was one of his few high-profile endorsements.
For Specter, who later became a Democrat, his pro-abortion-rights position was a centerpiece of his campaign. Specter believed that anti-abortion activists were a “fringe” group hijacking the Republican party.
“There are clearly more Republicans who are pro-choice,” Specter told Newsday’s Susan Page. “Up until now, I am the only person willing to take on the fringe.” After Specter dropped out of the race, he led an ill-fated movement to change the anti-abortion provision in the Republican party platform.
Santorum was effectively returning a favor by endorsing Specter despite his aggressive pro-abortion-rights views. Specter had supported Santorum’s 1994 Senate campaign.”