This is an excellent article from Dale Beran that helps explain the connection from 4chan to Trump supporters:
How did we get here? What is 4chan exactly? And how did a website about anime become the avant garde of the far right? Mixed up with fascist movements, international intrigue, and Trump iconography? How do we interpret it all?
When it was discovered that Trump had bragged about sexually assaulting many women, it made sense to me that Trump supporters would have continued supporting him. Why not, they may have made mistakes in approaching women, or even done things that amount to assault, themselves.