A (traditional) filibuster is what one Senator uses when he does not have the 41 votes necessary to stop a motion from coming before the Chamber. When the Dums have more than 40 votes they can stop anything that Frist wants to bring up. When something has been "stopped" other rules come into play to keep said motion or plan or bill from being presented again. So Frist would be shutting down Republican initiatives by his own action.
Then do it.
Trashing a 55 seat majority for the illusory "someday" of 60 seats is, quite frankly, insane.
This really is a question of adopting some backbone, and setting aside Senatorial comity until the lesson has been taught.