One of the great stories of English constitutional history is the development of strong Anglo-Saxon kingship. Under the leadership of figures like Alfred the Great, Anglo-Saxon rulers were able to regulate and ultimately abolish the kin-based blood feud as a mode of dispute resolution.
There is an alternative explanation for English exceptionalism, rooted in culture. This case is made in a recent book by James C. Bennett and Michael J. Lotus, called America 3.0. They in turn draw on other works, notably Alan MacFarlane’s The Origins of English Individualism. They take the view that the causality runs from the nuclear-family culture of the English to the path of institutional development that emerged in England (and later in America), more than the other way around.
For example, in a clan-based system, land can be owned collectively and allocated according to traditions as administered by the clan leaders. In a nuclear-family system, families need to be able to obtain their own land, which requires a system for exchanging land. This leads to concerns with property rights.
Bennett and Lotus argue that our nuclear-family culture is not going to disappear, given that it has a thousand-year history behind it. And they suggest that our central government has become so awkward and misaligned with the information age that a new era of decentralization is likely. What they foresee is neither a libertarian quasi-anarchy nor the Washington-centric welfare state that we have now.
Anyway, the issue that you might address is whether the English and American cultures have embedded within them a strong resistance to the clan form of society and if so, whether that means that we could see a less powerful central government without the emergence of an order based on rule-of-the-clan.