What word might one use to describe this sort of lying other than “contempt”?

This line reflects unmitigated contempt for her audience — which, given KJP’s job, is the entire American public. She knows what she’s saying isn’t true. And she knows that everyone knows that what she’s saying isn’t true. 77 percent of Americans — including 69 percent of Democrats — believe that Joe Biden is “too old to be effective for four more years.” They believe that because they can see it. Of course Biden is not hard to keep up with. Of course Biden is not constantly working every day. He’s barely alive. Who, exactly, are these lies supposed to move?