From the comments:
Napolitano is the Fox News senior judicial analyst and has been on the air for years. They gave him a segment to air his views and promote his book. He has spoken in defense of liberty every chance they have given him. The Judge is a Ron Paul supporter, and has passionately promoted his presidency - you can find a video of this on youtube. Some Paul supporters hope to see him as Attorney General one day.
Sounds okay to me!