Why is this controversial? Of course Senators and their staffs look at the political angles and possible fallout before getting involved in proposed legislation. Of course they think about how it will affect both parties. That's politics. Many of them do want to do right and help people, but they are elected in a political process, answer to their constituents in a political process, and operate daily in a political process.
Because the public already thought Congress was getting involved in the Schiavo case for political reasons. This just confirms it, and gives the Democrats ammunition. Not to mention that conservative pundits spent all last week talking this down as a fabrication, and now have egg on their faces. Stupid, stupid, stupid. Not a good week for the GOP.
BTTT
Because it was poorly written.
You are correct that this kind of analysis is routine in both parties, the writer was careless in not establishing that Pubbies were interested only in saving Terri's life, not political capital for Pubbies.
This document could have been worded so that it's release to the media would have hurt only Rats.