Quite frankly, they don't have to. Pillorying him in death will make him a powerful martyr. Saying nothing and ignoring the story as it grows in social media will make him a powerful martyr. The more the Left speaks evil of Kirk in death, the more powerful his death becomes politically. MLK's death was no different, as but one example.
The Left--and I assume it was a Leftist that shot Kirk--fucked up. They screwed the pooch. They made a martyr out of someone they shouldn't have. Just like with MLK--and no, that isn't a direct comparison so much as a general one--they assassinated someone who had a movement behind him. That will cement the movement and draw sympathizers to it. Charlie Kirk's death will have a huge and negative influence on the 2026 election cycle for Democrats.