The central criticism Madison refutes in the essay is that the House of Representatives will comprise legislators having the "least sympathy with the mass of the people," and that they will be likely to coalesce in the "ambitious sacrifice of the many to the aggrandizement of the few."
Reassuring the reader first of the general properties of republics which prevent tyranny, namely elections and term limits for people in a public trust, he moves more specifically to the safeguards present in the United States Constitution for that purpose.
Third, selfish motives of human nature bind the representative to his constituents because the delegates hope to seek advancement from his followers rather than the government.
Fourth, frequent elections remind the representatives that they are dependent on the constituents for their loyalty and support.
Moreover, he questions the practicality of a small pool of electors logistically, and ends citing examples in contemporary state constitutions of large bodies of voters which nevertheless elect fit representatives.