Once, in his days as New York’s chief federal prosecutor and later as the city’s mayor, Rudolph W. Giuliani was a master of releasing damaging leaks aimed at the kneecaps of opponents. Sometimes, they were true.

Now Mr. Giuliani works the other end of the information slurry, and he has had a hard time keeping his stories straight, one day boasting of his inside sources, then denying that they exist.

At a Senate hearing this week in Washington, Democrats took turns at the microphone to ask about the furies that — depending on which version of Mr. Giuliani you believe — ran from the F.B.I. office in New York to Mr. Giuliani during the closing weeks of the 2016 presidential election.

One Democratic senator asked the F.B.I. director, Christopher Wray, if the pipeline was still running.