Is it just me, or does it seem like this presidential political campaign has been going on forever? Back in June of 07 (!) I mentioned that the media was reporting Senator Barack Obama had been given the call sign of "Renegade" by the US Secret Service:
http://mt-fedfiles.blogspot.com/2007/06/secret-service-call-signs.html
I can confirm this is still the case. During a recent visit to the state of Oregon, Senator Obama's security detail was using 165.3750 MHz, P-25 digital mode. And he is still being called RENEGADE.
The security details are using various USSS frequencies depending on the location and detail requirements:
http://mt-fedfiles.blogspot.com/2008/02/secret-service-frequency-list.html