Let's paint a scenario that could be true. Is it true? I don't know.
I've had the displeasure of having to deal with the Deep State most of my life. If you haven't gone to Harvard, like me, you've probably been spared the experience. The Deep State is one sick puppy. I'm not a doctor, but I do get barfed on. They can, and do, spy on anything they want, via modern electronics. (They used to use more traditional bugging with telephones.) After decades of this, they've perfected the technique.
How do they do this? Watch the movie "Videodrome", from a few decades ago. Ignore all of the brain tumor stuff in the movie, and that's how they do it. In Videodrome they use the television, but they can just as easily use radio or magazines. The Deep State can set the narrative without ever personally appearing. They just need access to the lines of communication. Ask Ed Snowden about that.
People are seeing an ambiguity as to the political thoughts of the guy who tried to assassinate Trump. If he was doing the bidding of the Deep State, they could have sent him out to assassinate Biden just as easily as Trump. He was doing a job, like a professional hit man. This thought may have just occurred to Biden, who found a Covid excuse not to be at an event in Las Vegas.
Now let's think about it. Is there any reason why there couldn't be a dozen or more such people floating around, willing to take orders to assassinate politicians? Welcome to the Deep State!
This is just theory. But it could be true.