I'm not confused about what white supremacy is. The sites listed are instructive: Breitbart has explicit white supremacist and Nazi ties [1], whereas InfoWars is often a gateway into white supremacy [2]. The Twitter link is a bunch of examples of Gab's official Twitter account making anti-Semitic comments.

[1] https://www.buzzfeednews.com/article/josephbernstein/heres-h...

[2] https://www.revealnews.org/blog/the-hate-report-infowars-is-...