Due to the massive size of the UEE, there are dozens, even hundreds of political parties but there are three that dominate the political landscape.
Universal Party - Institution-focused ideology. Government and systems will guide the people. Seen by some as a blue-blood, wealth-based ideology.
Centralist Party - Traditional even somewhat libertarian-styled political ideology. It’s about sustaining and maintaining the status quo, and excelling through the values of humanity. Embrace the past, be proud of where you came from, etc. Needless to say, they support keeping Earth as the capital.
Transitionalists (Transits) - Relatively recent “People’s Party” formed around promoting a progressive human agenda. Most of their rhetoric is aimed towards “the future.” They obviously support Terra as the center of the UEE.
Source: Writer's Guide: Part Two