If the constitution and the political dynamics are designed for bi-partisan system it’s pretty hard to evolve out of it. A third party can also play as the king maker and have an unfair influence compared to its size. Some countries have a more dynamic coalition system but that has biases as well.

Couldn’t Orban argue he was corrupting the US gov. in order to get their good favor ? Since the US has a legal way of doing it there was no reason to involve diplomats and intelligence services.