The reason that the far Right has had such a field day with this is because the Left has been so inept and self-deluding.
The events in Kenosha provide a clear repudiation of the idea that citizen policing + permissive open carry is a good idea. "Two extra-judicial death sentences" is an atrocious outcome for anyone who even tries to pretend that they like the rule of law. It's a disaster.
If the Left had played up THAT angle hard, instead of basically lying about Rittenhouse's (very well documented!!) actions, then the Right would have had nothing much to do except slink off into a corner.
I continually marvel at how the Left manages to snatch defeat from the jaws of victory. Good grief! This one was such a clear victory for the "trained professionals, not random vigilantes" camp...and somehow ideology and dishonesty-for-a-good-cause managed to turn it into a defeat.
The Left should have been running stories about how Rittenhouse was acquitted, as of course he should have been (on the charges that were brought), but wondering about whether Illinois' mental health services are up to the task of giving him the support he'll need after having murdered two people, reflecting on how important professional training is in dangerous situations, talking about how we can do better at not getting people into potentially lethal scenarios where kill-or-be-killed is the only option, and so on.
Now Kyle's got a bunch of horrible people who want to be his best buddies. And most of what the Left is saying (on social media) is at best misleading and at worst lies. I don't see how this is going to go well for anyone.