@LouisIngenthron Nope not at all. For example the bull moose party (also called progressive party but seperate from democrats) replaced republicans for one election as the second major party. They had no representation at the time in congress or presidential, yet in one election they took over majority from republicans and began winning congress with no prior support.
This is the one example of a third party that disapeared shortly after. Other parties hiwever with a similar pattern in the past took over and kept control pushi g out one of tbe two main parties.
What your missing is FPTP voting makes it haplen this way, take kvver happens abruptly with no warning and shoots to majority almost overnigght. This is due to coalition effects.