Going way over the left and constantly attacking the patriot act or supporting leftist causes. Rick is a true conservtive in a blue state and Specter makes it very, very tough for him.
Uh, no.
First, Specter's lifetime ACU rating is 45. Not stellar, but he his not a supporter of "leftist" causes. Specter is generally on the right side of law enforcement issues. He is also generally on the right side of national defense issues. Discounting his pro-life position--which is ridiculously far left by the standards of Social Conservatives--he actually has a much stronger Republican position than you think. He is about where (unfortunately), Northeastern Republicans generally are.
On judicial appointments--some idiotic statements made right after reelection notwithstanding--Specter has been much more solid than most Conservatives give him credit for; He was very solidly behind Clarence Thomas and called Anita Hill and her cronies testimony before the Judiciary Committee "flat out perjury." He is also not one of the Republican gang of seven who betrayed us on the filibuster of Federal judges. For that, you can thank among several, the supposedly "conservative" John McCain, and the supposedly "conservative" Lindsey Graham.
Whatever his positions, they do not harm Santorum. There are plenty of states where one Senator is very conservative and has a more left-leaning counterpart, of the same or a different party. Not unusual, and in some ways it convinces Perotista's, moderates, and other un-serious voters that they have some cover to vote for the conservative because his views are "balanced" out by the other Senator.
Finally, you talk about Pennsylvania being a Blue State. Hardly. Our legislature has been dominated by Republicans for years, and so were our governorships until Rendell. We have had two Republican Senators for many, many years (there was a brief time when a Democrat served an interim period after John Heinz's death.) Take a look at this map, and you can see exactly how "blue" Pennsylvania is. The blue counties in Western Pennsylvania are actually not very populous, and are centered around Pittsburgh, a union town. But Pennsylvania's big problem is in the five eastern counties around Philadelphia. Those 5 counties and the city of Filthydelphia are the sole reason Pennsylvania did not go very very solidly for Bush. In fact, in that respect, Bush is quite an anomaly: no Republican except GWB has ever won the Presidency without winning Pennsylvania. None.
Those five counties are Specter's power base. He knows Santorum helped him with a tough primary challenge, and he is going to actively campaign for Santorum in that area.
I'm far from being a fan of Snarlin' Arlen. I worked for Toomey and I contributed generously to Toomey. But, at the end of the day Toomey endorsed Specter, and Specter will help (to the extent it's possible)--not hurt--Santorum.