@joefromchicago,
It's difficult to ferret out the range of motives and rationales here re the open arms, roses and chocolate boxes for Arlen. And it does seem that in the short term, a 'solid' Dem might have been preferable. Either Rendell, Reid and others saw benefits we can't see or buddyhood won out.
But in either case, I'm pleased with this event. The main point of discussion which has fallen out from Specter's move has been as regards the "too far right" position of the modern party. That seems to me not merely historically correct but politically advantageous at this point in time. For the same reasons that Carville and Begala set to the task of painting Limbaugh as the heart or directorial head of the party, this move and discussion puts attention on the extremity of the present party. And that's a very good thing.
As you likely know, Joe, three polls have just come out which put Republican self-identification at 20 % or a point or two higher. Given the hold on primary nominations by the more extreme components of the party (not to mention the hold on media operations by the usual customers) it looks certain to me that the party isn't going to change markedly until another electoral debacle or perhaps two.
Between now and then, barring the weird and unforeseen, what we have seen now in terms of infighting will likely be seriously trumped. What is it going to take to oust Norquist from his levers of power? He ain't going to go easily.