In the last two Congresses, Republicans have abused the filibuster to the point of creating an effective extra-Constitutional 60-vote requirement for any Senate action. Despite this, few Democrats seem willing to even seriously weaken the filibuster. They justify their refusal to do anything serious to control the problem by invoking the prospect of some future Congress when Democrats will be in the minority, and will need that strong filibuster as their only way to prevent some serious mischief at the hands of the then majority.
The flaw in this thinking is simple. It assumes that the Republicans will repay our forebearance now in allowing a strong filibuster to continue, with their own forebearance if and when they retake the majority. We don't have to guess to know that this simply isn't true. Their use of the Nuclear Option in the 109th Congress proves that they have no intention of allowing the filibuster to be used by any minority to block actions that they truly want.
We should not allow the filibuster to survive in any form that allows the Republicans any power to double-cross the nation in the future by using the Nuclear Option. Only the Legal Option -- embodying any filibuster in a public law -- allows sufficient protection against a double cross.