In the USA our system of two major political parties is a “parliament by other means.”
In Europe a dozen or more small parties run candidates.
After an election, successful small party candidates join larger coalitions in an attempt to create a majority.
In the USA if a small party is successful in some way, it’s best policies are quickly folded into one or both of the major parties.
In the USA we make our coalitions BEFORE the election.
In parliamentary nations, coalitions are made AFTER the election.
Congratulations on understanding how our party system works. My experience is that maybe 1 in 100 Americans understand these basic facts.
It’s why we’ve only really ever had two major parties. When one falls apart, another appears almost by magic by a splitting of the one still standing. This has essentially happened twice in our history: when the Whigs grew out of a split Democratic party, and when the GOP grew out of the wreckage of the Know-Nothing and Whig parties, joined by dissident Democrats tired of being pushed around by the slaveocracy.