I actually think if you remove yourself from what you previously read on Twitter and objectively review the evidence on this case you'll understand the verdict to be the right one. I'm a leftie and was totally bought into Rittenhouse being a murderer who went there to kill people. Some falsehoods:
"Rittenhouse crossed state lines with an assault rifle, travelling some way to join a counter protest."
No, he worked in Kenosha and his dad lived there. The gun was given to him by a friend to defend himself. I think walking around with a rifle is insane but a number of the protesters were also armed. Apparently he had provided first aid that day and a business owner had asked him to protect his business that night (there's eyewitness testimony to back this up)
Rittenhouse wasn't the aggressor. He was confronted and chased by an erratic, aggressive, mentally ill man who was only there to join a riot. A man who was actively racist himself and who also grabbed for his gun. Rittenhouse at the time was there to put out a fire. A shot was fired by a third man so Rittenhouse fired at the man chasing him on the assumption he was being shot at.
He then left the scene and was pursued by multiple men. He was beaten with a skateboard and a gun pointed at his head. It was chaotic. They believed they were taking down an active shooter, Rittenhouse, believed his life was at risk, so he shot out again.
I'm not saying he's some kind of hero. He might be a racist, is likely right wing. He's certainly a bit of a fucking idiot, but if you look at the details of the case impartially, the self defence argument is strong.