In part, for example, the idea was that any revenue spending by the government would inevitably be followed by revenue collection by the government and therefore by a need for the yeoman farmers to have cash money to pay the revenue collectors. The transition from barter and subsistence farming to a cash economy on any large scale would transform these people from the independence of their lives. Jefferson, and the later Madison, consistently opposed government projects of any kind. Many of Jefferson's positions, taken out of context, sound like the Republican freshmen of the last Congress. It's all enough to make one believe in the necessity of evaluating issues on their merits rather than simply following one's party.
Democracy is subject to possible abuses.
And commentators throughout history have argued that the mob would be better off under the tutelage of, variously, kings, aristocrats, priests, oligarchs, or populist demagogues. Jefferson et al are at their most moving when refuting and refusing these offers. It has been noted that the Framers of the American Constitution, when placed in the position of giving this sort of thought, created a government with little efficiency and often only slowly responsive to the will of the people. In fact, commentators like James MacGregor Burns, surveying the elaborateness of the system of checks and balances, have felt that the only conclusion can be that the Framers intended this very inefficiency and unresponsiveness. There is a form of democracy that ensures the success of the majority, but there are other forms.