Constantine the Philosopher University in Slovakia has completed a seemingly-silly study in which they analyzed the filled pauses of our Supreme Court. They found that Judge Kennedy used the most pauses and Ginsburg used the least, but they all favored "um" over the seldom used "uh," "ah," and "eh."
Unless I'm misreading the stilted conclusion, it appears that the justices were more likely to give a favorable conclusion if the content of the filled pause was closer to the one used by the arguing attorney.
The Annals of Improbable Research has more.
The study can be found here: ‘Entrainment in spontaneous speech: the case of filled pauses in Supreme Court hearings’ Proceedings of the 3rd IEEE Conference on Cognitive Infocommunications 2012.