Senators aren't affiliated with any parties because they're not representing parties unlike congress, but are representing major streams.
Article 6: Senate
Section 1: The Senate shall be formed of at least 15 members. Anyone is welcome to join the Senate if they so wish as long as they have their paperwork in order, have obtained a free voter ID from the Imgflip DMV, and have been elected or appointed by a stream to represent them. No government stream including IMGFLIP_PRESIDENTS, political party stream, or stream that provides a service to PRESIDENTS such as IMGFLIP_BANK or IMGFLIP_DMV may appoint a Senator.
Key point from Article 6 Section 1: and have been elected or appointed by a stream to represent them.
Let me compare senate and congress from this stream to the US senate and house.
The Senate on this stream is supposed to be bipartisan but instead vote for what the stream believes, a stream is like a state. Senators in the US represent entire states.
But Congress on this stream is supposed to represented by parties, to which they have certain amount of seats given from election results, with the cap of congress seats being like the amount of Congressional Districts from Imgflip_Presidents, which is a stream and is like a state.
Overall, senators aren't affiliated with parties at all, but good try