This term refers to any political group- other than democrats and republicans- that attempts to get their candidates elected to public office.

Third party.

Explanation:

Third parties have sometimes launched large campaigns and have won public offices, but have not obtained significant or consistent representation in the federal government.  A third party could change the state’s winner in one of these states by gaining enough votes that would have otherwise gone to a major party. If the election is equally close this time, a third party potentially could determine the outcome by claiming only a small share of the vote. The most likely scenario for a third party influencing the election could be upsetting a close race

one of the major compromises in the constitutional convention was between the small states and big states. the small states wanted each state to have the same number of representatives in congress. the big states wanted representation based on population.