I appreciate that - I'm familiar with Condorcet's and Arrow's theorems. I'm not a fan of FPTP myself (as I come from a country with proportional representation, and quite like that it's how local elections are run where I live); I just don't think it's deliberately engineered to effectively prevent the formation of other parties, although I certainly agree that it's frequently gamed to that end.
FPTP itself is not deliberately engineered to lead to two parties and I doubt that was the intent of the framers anyways. For a time at the beginning of U.S. government the whole notion of strong political parties was considered bad for governance anyways; people were supposed to represent their constituents or their state.
However nowadays the two major parties certainly do cooperate in ensuring that there remain only two major parties, rather aggressively going even further than FPTP would otherwise lead to in keeping additional political parties weak. It's easier to get elected without a party affiliation at all than to be elected as a party other than D or R.
> I just don't think it's deliberately engineered to effectively prevent the formation of other parties
Whether it is "deliberately engineered" to do that or not, it has a fairly well-demonstrated effect of doing that compared to systems which provide more proportional results. Intent is pretty much irrelevant.
