Not a single senator could be persuaded to support the treaty, which has not been brought back to the floor since.

But under the impeachment rules adopted unanimously by the Senate, a single senator could block such a move.

And it was opposed by every single senator at the time who now seeks higher office.

The president did not bounce the name of Roberts off a single Democratic senator.

It's not believable that one single senator would be able to pass an expanded tax bill.

But not a single Republican senator interviewed was willing to take credit for the proposed rebate.

Not a single Republican senator was working with the Administration on health care, or much else.

In others, a single senator exercising a "hold" can derail an appointment.

Senate rules would permit a single senator to block the bill because it increases the deficit.

What is more, not a single senator raised an objection, he said.