IIRC that would require a rules change. The rules for a fillibuster were changed quite a few years ago. It now takes 3/5 of the senators SWORN to invoke cloture. In the past (Mr. Smith Goes to Washington) it was 3/5 of the senators PRESENT
(I prefer the old way - make them work for their dissent...)
It's exasperating watching the liberals drag this out, but at least Judge Alito will finally be confirmed. That's what counts. And if the liberals are damaging the Democrat Party with all of their histrionics, then it's worth waiting them out.
At the time of Mr Smith, I don't think they had cloture votes. At least they didn't bring it up in the movie -- and there was NOBODY who supported smith there, so he would have lost a cloture vote.
How about the old days in the 19th and early 20th century when there was NO cloture? (Imagine a world without cloture.) Virtually the only way debate could be cut off was by unaninmous consent.