Examples
In the commercial, it starts off by saying that John McCain knows nothing about the economy and he also doesn't the know the number of houses he owns. Those two topics have no relevance to each other. Talking about McCain's houses was a red herring.
In the comic, the red herring character is trying be a distraction to stop the "Scientific Challenges to Evolution" by bringing up the topic of separation of church and state. The red herring wants to be a distraction.