I am not an American either, but there is a great deal of work on this subject, and the two-party system is actually one of the most resistant to single-individual or single-party takeover. The reason is that multi-party systems are vulnerable to having a party in power 'promoting diversity' (or something similar), in order to disempower all their opponents, while making it look like they're allowing for more views. Examples of this include quotas for minority representation, and (strategically designed) multi-member voting districts.
https://en.wikipedia.org/wiki/The_Logic_of_Political_Surviva...