They were active in the abolintionists movement. :)
Answer:
People with the same general views started to group together and this created the political parties. Two main groups prevailed and had very different views and this led to them sticking around.
1. The politicians needed more votes than they could get by just running on their own with out the support of a party
2. When America was founded there were 2 main opposing view and these parties gain the support of most citizens and pushed smaller parties out of the political spotlight
Explanation:
Mostly likely answer is: Diplomatic Immunity.