The circumstances have changed.
We are 5 years into Obama's presidency and the hyper-partisanship showed no signs of abating. The old rules worked because there were moderates in both parties whose ideas overlapped. And there was a deference to the constitution where it said presidents pick their cabinet and appoint judges to vacant seats. There's no ambiguity in the constitution on that. That moderation and deference is no longer the case, thus the utter dysfunction in the Senate, until now.