Any senator may demand a roll call at any moment to establish the quorum.

Already, several conservative Republican senators are demanding that the Senate complete the trial and vote on conviction before "negotiating" a censure deal.

Republican senators and President Bush have demanded a straight up-or-down vote.

Several senators demanded that he not write while serving as the Congressional librarian.

The senator demands the stock tip outright and threatens Durant with prison for remaining silent.

Any senator could demand a quorum call (with the cry of numera), which required a count of the senators present.

But a senator and two House members, all Democrats, have demanded a fuller accounting.

First eight Republican senators from Long Island had demanded more school aid.

The senators demand a yes or no answer.

At a recent Congressional hearing, senators from both parties demanded that oil executives defend their record profits.