From the Workforce Washington Blog:
So far, President-elect Barack Obama's Cabinet and White House appointments have had a "dog in the nighttime" effect on Republicans. The selections, like the intruder in the Sherlock Holmes mystery, haven't made them bark.
The reason the dog remained quiet, Holmes deduced, is because he knew the late-night visitor who stole the race horse Silver Blaze before a major race. The dog's sanguine reaction helped the fictional detective narrow the list of suspects.
Similar to the stable dog, Republicans have kept quiet-or even voiced support-of Obama's choices for economic and national security leadership positions.