Wow! It is possible for a country to elect a lady, and more! Is also a scientist & enviornmentalist...Claudia Sheinbaum

[Celerity]

10. the US Constitution never mentions political parties

you said

Because the US has a 2-party system written in to our Constitution

https://en.wikipedia.org/wiki/Political_parties_in_the_United_States

snip

Political parties are not mentioned in the U.S. Constitution, which predates the party system. The two-party system is based on laws, party rules, and custom. Several third parties also operate in the U.S. and occasionally have a member elected to local office; some of the larger ones include the Constitution, Green, Alliance, and Libertarian parties, with the latter being the largest third party since the 1980s. A small number of members of the U.S. Congress, a larger number of political candidates, and a good many voters (35–45%) have no party affiliation. However, most self-described independents consistently support one of the two major parties when it comes time to vote, and members of Congress with no political party affiliation caucus to pursue common legislative objectives with either the Democrats or Republicans.

The system of elections is what causes a default to 2 parties.

There is no proportional representation, and both the US Senate and the US House seats are filled by a single winner being elected by a plurality (unless a state requires a run-off, should no one candidate garner 50 percent + 1 vote), with the further addition of the US House consisting of single member districts (the US Senate seats are statewide, of course).