I recently attended both NJ Boys State and Boys Nation this past summer.
Both were amazing and vastly different experiences. It goes so far beyond the "points" that are added to an ROTC, SA, or regular college application. The two experiences took skills I thought I had developed well and transformed them even further. It instilled the values and importance of democracy & free/fair elections.
I think its efficacy can be attributed to the fact that delegates actually live in the lesson being taught about democracy—it's what's being done from when they wake up in the morning to when they sleep at night. At least in NJ, the experience is completely in the hands of the delegates. There's no political agenda pushed at all, and the ideas presented are those of that year's statesman. I saw conservative and progressive people get elected to all different sorts of spots at Boys State and Boys Nation. You all wear the same clothing all week, symbolic that everyone there is the same and that there's only one thing that matters in "performing" in elections or leadership: your ability.