A political system in which only two parties have a reasonable chance of winning is called a two party system. A unitary system of government, ultimate government authority is located at the national or central level.
When the only candidates who have a reasonable chance of winning an election are one of two parties, this is generally referred to as a two party system. The US is an example of a two party system in which the only candidates who stand a reasonable chance of winning are Republican or Democratic.
2 Democrat or Republican. If you are a third party candidate, you have practically no chance of winning.
an Advantage is that Smaller parties get a better chance of winning an election
As I understand it (I am British) the 2 political parties (Republican & Democrat) choose a leader who is then voted for by universal adult suffrage. The parties each elect a candidate & the people have a choice of these two. There may be other candidates, but it appears to me that these do not have any chance of actually winning.
Political parties select their candidates for president after the primary elections. They go to their parties convention and cast votes for the person they think has a better chance to be elected.
Chance of winning: 2.78%
Chance of winning: 4.76%
Chance of winning: 0.99%
Chance of winning: 5.56%
Chance of winning: 12.5%
That means that you have a very slim chance of winning. About a 10% chance of you winning, and a 90% chance of the others winning.
I will tell you candidly, that you have no chance of winning.