Having never seen West Wing, I thought the voice sounded a lot like Katey Segal (Sons of Anarchy).
http://www.theivrvoice.com
Alexander Gould
Voice overs, aside from being the coolest career imaginable, are the voice talent you hear (but cannot see) when watching cartoons, web videos, TV commercials, radio, audiobooks, documentaries etc....
Alexander Gould provides the voice of Nemo .