Yes, of course Mario Cuomo was a politician, but he was the voice for liberals and progressives at a time when there were few. We have to remember the time. The mid to late 1980s, it was so unpopular to be tagged a liberal.
Governor Paterson, if you haven't done so already, give William Jefferson Clinton a call and see if he's interested. It is not unprecedented. Two former presidents have served in the U.S. Congress in the past.