"We shouldn't kill the filibuster because we may need to use it in the future" is like

[qazplm135]

5. Not really

The filibuster does good and bad things.

It keeps them from doing anything too crazy, but keeps us from doing good things.

Now, one can argue that the latter is more important than the former, but one cannot argue that the former isn't a real threat.

If you believe that passing our bills will lead to our long-term ascendancy then it makes sense.
If you believe that we will continue to yo-yo between the parties, then it makes less sense.