Why haven’t the spooks heart-attacked him? It’d be the perfect solution. Nobody need be the wiser. Just a quick hypo via disguised ring, and he’s gone, along with his whole degenerate clan. And Kamala can do some ataxic, bad imitation of Harry Truman without the character, the smarts or the experience of the latter. Donald Trump vs. Cackles the Clownette.
Plan A is to get him to decide not to run.
Plan B is to invoke the 25th Amendment.
Plan C may be what you suggest.