Technically, a militia can be one. That's why the ruling against gun control ordinances in Chicago and DC and the declaration that bearing arms is an individual right (since an individual can be a militia).
That said, the men in Oregon probably figured (correctly) that any kind of effigy or symbolic protest would be ignored (unlike in Europe, men of power in America can usually overlook these kinds of things as just self-expression and not a direct attack on them personally). If you want to get an American politician's attention, you're going to have to be somewhat more forceful in your expression.
Biting the hand that feeds IT
