senator switches parties

I just read on the internet that apparently longtime Republican Senator Arlen Specter has switched parties from Republican to Democrat. I'm neither a Republican nor a Democrat. I'm an independent. Both parties have a lot of problems. It doesn't make much sense though that someone who has been in the Senate for as long as Specter has could just change parties. Thats pretty strange but it shows that the political party system in Washington doesn't make a whole lot of sense. It is rumored that he was going to lose the Republican primary in Pennsylvania and that might have played a big part in why he might have changed parties. It seems like most politicians only care about getting re-elected and some of them probably vote certain ways on issues just to get re-elected.