Why Pombo has to be removed ... safely

So, here's the deal. Our dear Richard Pombo voted against all of Flake's amendments.
http://www.clubforgrowth.org/2006/07/435_districts_435_blogs_agains.php

He really needs a boot in the butt. The problem is, doing so in general election is going to give Democrats the seat, and we all know how hard it is to unseat anyone. So, the main battle is in the primaries.