I felt that the most interesting (and original) concept that Smith raised was how groups or individuals who are losing an insider argument will leak information to the press in order to "widen the circle" and signal their supporters about the need to become involved with the issue or risk defeat. It seems to be a very useful explanatory narrative to keep in mind when reading media stories based on leaks.
Although I have no proof, after reading Smith this weekend I wondered if this idea applied to the recent media discussion over whether it's feasible or necessary for states to be able to declare bankruptcy in order to deal with their sizable deficits. For instance, this NY Times article and earlier ones discussed how policymakers were discussing bankruptcy options due to fears over state deficits. This option has been discussed for weeks, prompting varied counterarguments from a diverse group of scholars and think tanks, including the Center on Budget and Policy Priorities where I am currently interning. Most recently, Eric Cantor (R-VA) came out against this idea, which had been pushed by Newt Gingrich. I wonder whether the initial articles that discussed "behind the scenes" efforts were prompted by leaks from those policymakers opposed to a state bankruptcy option that they feared was possibly coming into vogue.