There is a word anti-partyism, but it doesn’t seem to be commonly used.

The literal answer to your literal question is called “believing that US politics should be non-partisan”.

https://en.wikipedia.org/wiki/Non-partisan_democracy
The US started as de facto non-partisan democracy. There is a de jure option.

https://en.wikipedia.org/wiki/Direct_democracy
Direct democracy would probably give less power to political parties, but there still could be voting blocs. An example:
https://en.wikipedia.org/wiki/Orthodox_Jewish_bloc_voting

Epstein also owned Great St James (67 ha, 165 acres), which shields the view of Little St James from the mainland.

https://en.wikipedia.org/wiki/Great_Saint_James%2C_U.S._Virgin_Islands

https://aeonsend.fandom.com/wiki/Thorn_Supply_Pile

https://bsky.app/profile/radosh.bsky.social/post/3luxpjmhb4k2l

It is a sobering thought that one of his NYT obituary writers died two years ago.