just guessing, but...
the usual traded non-votes,for those
who, for some reason, believe the otherwise
apparanly generous Congressional vacation
schedule just won't suffice.
not sure how non-vote-matching
handles Senator Vegetable
I don't think your vote trading comment really applies here, except perhaps to people like Specter or Coleman. And it's not so much vote trading as it is them possibly voting for cloture because they knew it had no chance of success and they figured they could handle the heat from their constituents.
But staying away from the vote alltogether and making a strong statement against the resolution and the entire process, as Senator McCain did, impresses me as an act of high principle. McCain's stock is very high with me right now.