1. I believe the answer is: Socialist
There are only two major parties in united states, the democratic and the republican party. Socialist party in united states tend to only have less than 10% of votes during the elections, which make them have very little influence in congress.
2. I believe the answer is: a group of people seeking to advance their ideas
The majority of countries in the world provide the citizens with the freedom to form their own political party. These parties usually based on a certain believe or principle and established in order to fight for a certain social, economical, or religious interests from a certain group of people.
3. I believe the answer is: a coalition
In a multiparty system, a coalition refer to the combination of power between two or more parties. When a coalition is formed, the votes that each party members have would be collected and given to a certain candidate which they've agreed to represent them.