Once the ink has dried, even the most hotly contested of immigration laws are likely to disappear from public view – at least until they reach the stage of field implementation. Between the highly visible policy stages of legislation and street-level enforcement, however, lies the regulatory realm occupied by senior executives. The day-to-day tasks performed by these leaders of executive agencies, cabinet ministers, and their immediate staffs range from choosing implementation priorities and corresponding performance indicators to deciding on budget allocation, drawing up agency rules, and supervising field offices. In fields of coercive social regulation, the executive politics of implementation, which largely takes place outside of public view, is a venue of conflict in its own right: ultimately, the setting of enforcement priorities determines who will be within, and who will be outside, the coercive reach of the state.

While few policy areas are immune to lapses in implementation, fields of coercive social regulation are particularly vulnerable to the emergence of implementation gaps. For one, policy goals such as immigration or crime control are simply too resource-intensive to allow for close-to-perfect enforcement. As Joel Migdal reminds us:

no matter how vaunted the bureaucracy, police, and military, officers of the state cannot stand on every corner ensuring that each person stop at the red light, drive on the right side of the road, cross at the crosswalk, [or] refrain from stealing and drug dealing … (Migdal, 2001, p. 251)

Given that complete implementation is beyond their reach, leaders of coercive bureaucracies are faced with a choice as to which legislative provisions to enforce, while exempting others from implementation. Whereas the constraint of resource scarcity is universal across bureaucratic contexts, the substance of implementation decisions is not.