Thinking about how popular forces might act in a constitutional order helps connect my last couple of posts (here and here) because it is during the period of a constitutional system that people either take constitutional acts (that is, act within the scope of the constitution) or act constitutionally (that is, take extra-constitutional acts that have constitutional implications).
Most obviously, of course, popular forces influence constitutional orders by taking constitutional acts. Depending on the provisions and customs of the constitutional system, these acts may have a variety of forms: People may act constitutionally by voting into office officials who promise (and in fact do) enact or effect constitutional change. In some constitutional orders, popular forces may use the vote to make constitutional changes more directly, by ratifying an amendment to the constitution, by passing referenda that enact (or repeal) constitutional provisions, or by recalling public officers or judges as punishment for taking certain sorts of constitutional acts.
Many constitutional systems also recognize a parallel track of constitutional acts that enable people to try to push for constitutional change or reform more indirectly, though speech, writing, petitions, or various sorts of protests. These speech acts typicallly have several audiences, most immediately they may be intended to change the minds of other people, to increase the numbers of the movement driving the calls for reform. At the same time, these popular protests may work more indirectly, by trying to influence a third party (ie, some agency or institution that is neither the people nor the targeted government). This might take the form of efforts to persuade the press, economic interests, local governments, or even other governments that a particular reform has popular support, moral credibility, or some other value. In this approach, the goal is to influence the third party to join in bringing pressure to bear for constitutional reform. And finally, these speech acts will have as their ultimate target those in the government who have the power to effect constitutional change.
At the other extreme are those moments when popular groups act constitutionally, when they undertake actions that have the force of constitutional power, but are not sanctioned by the constitution. When a mob takes the law into its own hands to enforce its own sense of justice, that mob is effectively assuming a variation of the police power, the sovereign power to protect the health, safety or welfare of the people. But the people may act constitutionally, by exercising a sovereign power to define the scope of legal protecctions or sanctions in less violent ways as well, for example when they refuse to abide with a particular legal demand.
In either instance, violent or not, the people may be acting constitutionally in several ways at once. On one hand, by denying the sovereign power of the state to declare and enforce laws, they are effectively laying claim to that sovereign power themselves. On the other, depending on the nature of the law they chose to ignore, they may be denying constitutional rights to others, effectively declaring those others outside the constitutional order.
There is a middle ground, on which people may engage in activities that can be characterized either as constitutional actions or acts that have constitutional significance. Here, the precise nature of the action may determine how it is characterized: a peaceful protest against a government may be a constitutional act, unless it is carried out on private property or by people whose right to protest is circumscribed (pubic employees, for example).
Or it may be that there is a dispute over the constitutionality of the popular act, as was the case during the nineteenth century when juries refused to enforce the fugitive slave acts. Some commentators argued that the jurors were exercising their sovereign power to decide the law, others asserted that they were engaged in unlawful acts of resistance that was tantamount to treason.
As that summary suggests, the roles of popular forces in a constitutional system can be viewed from several perspectives. We can think of them as existing on the continuum that stretches from constitutional acts (speech, the vote) to acting constitutionally (the vigilante mob). Alternatively, we can consider the acts on a spectrum that spans violent actions (the lynch mob) and peaceful protests (the petition). We can organize them by institutional and quasi-institutional categories, noting, for example, that some popular acts are exercised during elections, some through the legal system, and some in the public sphere. Or we can arrange them by their relation to the concept of sovereignty: with some actions being taken to influence the sovereign (protests, petitions), while others are taken by the people claiming to be sovereign (referenda, jury nullification, vigilante actions).