So what? Santorum endorsed pro-abortion liberal Arlen Specter over conservative pro-life Pat Toomey in 2006. It wasnt the first time he endorsed Specter - Santorum also endorsed Arlen Specter early in his 1996 Presidential run.
http://archive.theamericanview.com/index.php?id=104
President Bush personally asked Santorum to endorse Specter, in exchange for Specter promising to push through Roberts and Alito. How many Republicans asked Newt to endorse Scozzafava? And Pat Toomey was one of only 8 Republicans to vote to repeal DADT - joining Snowe and Collins. Some "conservative".