Let me begin by saying that I don't really care what Arlen does. I think his actions speak volumes about WHO he is and WHAT he ultimately stands for.
When he switched parties before (regardless of the stated reason; Reaganism or not), it was about doing what it took to stay in office. At that time, he sensed a 'sea change' in his constituency, and acted with that in mind. Now, once again, he is doing the same - he estimates (and he is most likely correct) that he has a better chance to remain in office by switching.
Whether he is ‘more valuable' to the Republicans than the Democrats is a moot point. I would caution both parties to consider – in the current ideological based, extremist approach to politics - can you rely on someone (politically) when his 'principles' are based on nothing more than what it takes to remain in office?
Have Republicans "moved to the Right". Possibly. Beyond where Spector stands? Absolutely. It is clear that his 'defection' and departure from the party line on numerous occasions has earned him the wrath of the current RNC leadership. If he remained an (R) beside his name, he would not have won the next election. And this move, when probably his best chance to remain in office, may not prove to be enough – we’ll see next year.
I disagree (slightly) with your statement, “This country needs two working political parties consisting of people who can think for themselves and who are capable of constructive dialogue.” We don’t need political parties – we need individuals who are willing to set aside the needs of the party for the good of the country (as they see it). I would much rather someone take a stand, according to their principles, and then stick to it. Jumping ship to save your self – or in the attempt to manipulate control over power within the party machine(s) - is ultimately a disservice to the public at large.
It goes without saying that I disavow your comment implying Spector was “a rational voice within the GOP”. Hardly. He was, however, a member of an isolated branch of the GOP-at-large that had more in common with what remains of the moderate wing of the Democrats. Adding a respected (albeit more moderate) voice to a group that has ALSO clearly moved in its own extreme - to the Left instead of the Right - unfortunately lends an air of respectability to those who have done nothing to deserve it.
BOTH PARTIES are virtually incapable of contributing meaningfully to the goal of providing a proper and function form of governance. A complete overhaul of the ‘party system’ as it currently exists is long overdue.
Where are the Whigs when you need ‘em?