I think all this misses the point of the U.S. system of politics. That system is based on a constitution adopted over two centuries ago and premised on the idea that good government consists of a government of limited powers with proper checks and balances in place to make sure it remains limited. The idea back then was to move away from the old systems of rule by royalty and to adopt a form of government that philosophically was based on the idea that all legitimate forms of power ultimately derived from the popular will but only as checked by systems that were designed to curtail the effects of mob rule, prejudice, and passions. Thus, the federal government was set up as a tripartite government, with a legislature, an executive, and a judicial branch. The legislature was to have a popularly elected component (the House of Representatives) but also one in the Senate that served to check the popular (Senators were not even elected by popular vote until the 20th century). The executive power was to be sharply curtailed by the specific grants given to it in the constitution and was not allowed to enact new laws but only to enforce those enacted by the legislature, with its tie to the popular will. The judicial branch, in turn, was to enforce the rule of law in a way that was far removed from popular sovereignty, with federal judges appointed for lifetime tenures (subject to approval by the Senate) and capable of being removed only on the narrow ground of committing an impeachable offense. Finally, with the federal power having been so defined and circumscribed, the constitution provided that all powers not expressly granted to the federal government were to be reserved to the states and to the people. A bill of rights was superimposed on top of all this, making clear that certain supervening rights of the individual could not be impaired by federal governmental authority (this eventually being broadened to encompass action by the states).
If you read the Federalist Papers, which were in essence arguments propounded at the time in support of adopting the U.S. Constitution, there is no naive assumption in these documents that pure popular rule would somehow become a pristine way of running a government. Indeed, it was just the opposite. In one after another of these documents, it is assumed that rule by pure popular will is basically evil and dangerous because people will be driven by baser motives to accomplish their ends. Thus, there is all sorts of concern about not allowing unswayed prejudices to run unchecked through the course of government. The point of the arguments was to recognize that this is the reality of how people think and act and to set up a system that deals with it while preserving freedom and holding public officials ultimately accountable to the people.
I think this system ultimately had a theistic base in a Judeo-Christian tradition that saw man as a fallen and fallible creature who was prone to all sorts of mischief when given a chance. This may be open to debate but it certainly was one important component of that era. In any case, the founders appeared to have no assumptions about the ability of people to rule themselves based on becoming progressively enlightened. Their approach was realistic and pragmatic and dealt with how to contain power so that it does not corrupt those given the authority to rule.
This piece has interesting elements in it about how people resist changing their minds based on new information but I think it is off in its implications of what this means for good government.