I feel like all the Sanders Sides could be argued nonbinary so here's that argument in the form of what I think they would respond to the question "What is your gender?" (In rainbow order)
* Roman
Very insecure about not feeling completely male and is in denial
"W-What?! I am very clearly a man! A manly man! A man who is manly......., Man!"
* Janus
Is very aware of what they identify as, but will not tell you
"My gender? Figure it out yourssself."
* Remus
Does not know what gender is, or chooses to ignore it
"Isn't gender that bug I ate last week? Her name was Gertrude!"
* Patton
Is very confused, but is happy to learn about whatever you're talking about
"Well I'm your Happy Pappy Patton Father Figure Figment! Fathers are men, so I guess that would make me one too! I think? Maybe? Help me out here, kiddo"
* Logan
Does not give a flying falsehood about gender
"I am not a "man" or a "woman". I am simply: Logic"
Yes he used air quotes
* Virgil
Avoids the question in the most subtle way possible
"What are you, a cop? Why are you asking about gender? (angry gasp) Are you trying to steal my identity?! Well you're not getting me this time, bucko!"
Very subtle
@thatsthat24