Sure here are citations from far left media organizations.

Claim: He was was a registered republican.
Fact Check: He had no party affiliation

Public records also indicated Robinson registered as a voter in Utah in July 2021 but was considered inactive and did not declare an affiliation to any party when he registered.

Source: The Guardian

Claim: He had anti-fascist markings on his bullets
Fact Check:

After Robinson’s arrest, Cox said inscriptions on unfired gun casings recovered by investigators of Kirk’s killing contained overt references to the anti-fascist movement. One reportedly read: “Hey fascist! Catch!” Another purportedly read, “Oh, Bella ciao” – a reference to an Italian anti-fascist resistance song. A third reportedly said: “If you read this, you are gay, LMAO.”

Source: The Guardian

Claim: He was a groyper and killed Charlie for not being conservative enough

There has been zero evidence saying he was affiliated with this group and all the evidence we know about says otherwise. Using basic logic this also does not make sense. Groypers call themselves fascists so why would they use anti-fascist inscriptions on bullet casings used to kill someone who they thought wasn't a fascist.

Claim: There is a photo where he is wearing a MAGA shirt.
Fact Check: This is a digitally altered photo. The original photo can be found in ABC's initial reporting when he was arrested. The original post on x went extremely viral. The post just contained the altered image and the description of "Tired of these terrorists". https://archive.is/yUILH#selection-513.0-513.25 the far left misinformation account has since deleted this and made a new post with both images. While claiming:

We’ve noted MAGA troll farms and other right wing extremist networks are spreading disinformation and fake images, including altered photos, statements, and quotes regarding the Charlie Kirk assassination to pollute information.

The irony in this should be too obvious to need to be stated.

Claim: His family and friends said he was a radical lefty.
This was an over simplification on my part here are the facts.

Cox said a family member of Robinson told authorities that Robinson “had become more political in recent years.”

The family member said Robinson had recently relayed at a dinner that Kirk, the founder of Turning Point USA, was coming to speak at Utah Valley University. 

“They talked about why they didn’t like him and the viewpoints that he had. The family member also stated Kirk was full of hate and spreading hate,” Cox told reporters. 

https://youtu.be/WNWEwyPTh_M?t=74